The 2nd Arc of the 1st season has as it's Shitennou Nephrite, the second strongest of the Shitennou (for reference Jadeite was the third strongest). Nephrite was originally stationed in North America but after the death of Jadeite he was reassigned to Far East to take Jadeite's place. Unlike Jadeite's whose youma were just creatures under his command Nephrite's youma were actually normal humans who were nearing their energy peak. Nephrite would have a youma spirit possess them which made the human turn evil and gave them superhuman abilities. When the human reached their energy peak the youma would take their energy and appear leaving the human uncouncious and dying unless their energy was returned. Please be aware that besides Nephrite there won't be a huge amount more feats either for the youma or for the Senshi.
Physical: In Episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!) Sailor Moon tanks being telekinetically slammed into the ground many times from the youma Tesuni.
Mental: In episode 18 (Shingo's Innocent Love! A Sorrowful French Doll!) Sailor Moon shows a bit of cleverness when she realizes her brother Shingo's friend Mika is being possessed by a youma even faster then Luna, who to remind you is a superintelligent cat, did.
Movement: Sailor Moon continues to show incredible reflexes in the Nephrite Arc. In episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!) she dodges a rain of the youma Tesuni's fireballs. However she displays an even greater feat in episode 17 (Is Usagi a Model? The Focus of the Monster Camera!) where she displays Faster then Light reflexes. No you did not read that incorrectly. And usually someone would say it's a genre inconsistency the same way lasers in fiction are not all light speed. Except she didn't dodge a light beam she dodged an actual flash of light, from a camera. Probably a high-end outlier but better to state it and be careful. However she also displays some faster movement feats to compliment her enhanced reaction feats. In episode 18 (Shingo's Innocent Love! A Sorrowful French Doll!) Sailor Moon shows on camera that she can move faster then the eye on screen as she disappears from the line of sight of Shingo and Mika.
Attacks: Sailor Moon shows another accuracy feat in the same episode where despite having just come out of the paralyzing grasp of the youma Jumeau's grasp she manages to hit the small weak spot of Jumeau on her left foot. It's not really that important to mention but just in case it should also be mentioned that in episode 23 (Wish Upon a Shooting Star! Naru's Pure Love!) Sailor Moon stops her own tiara in mid-air to prevent it from hitting Naru.
Sailor Moon is also shown to have a melee attack in episode 17 (Is Usagi a Model? The Focus of the Monster Camera!) called Sailor Moon Kick where she shows that she can kick humans or youma back several meters with a kick.
Physical: In episode 22 (Romance Under the Moon! Usagi's First Kiss!) Sailor Mercury still uses the Bubble Spray despite the paralyzing dark energy waves hitting the Senshi.
Mental: In episode 21 (Protect the Children's Dreams! Friendship Linked by Anime!) upon seeing Nephrite's disguised form for the first time Sailor Mercury almost immediatly realizes that it is Nephrite.
Attacks: Sailor Mercury's Bubble Spray actually shows some offensive use in this arc. In episode 15 (Usagi is Frantic! Rei's First Date!) Sailor Mercury's Bubble Spray knocks out all the forest animals controlled by the youma Petasos. Besides knocking animals out cold it has also shown the ability to cancel out energy, in episode 22 (Romance Under the Moon! Usagi's First Kiss!) Sailor Mercury's Bubble Spray neutralizes the paralyzing dark energy waves.
Attacks: Sailor Mars's attacks become notably more versatile in this arc, in episode 18 (Shingo's Innocent Love! A Sorrowful French Doll) she displays the ability to use multiple magical ofudas at once against the youma Jumeau's detached limbs.
Also in episode 22 (Romance Under the Moon! Usagi's First Kiss!) Sailor Mars's Fire Soul burns an entire courtyard-sized area when used against Nephrite's Soul Shadow at the embassy of the Diamond Kingdom.
Other Powers: Sailor Mars's abilities as a priestess also get noticably stronger. In episode 20 (The Summer! The Ocean! Our Youth! And a Ghost Too!) Sailor Mars manages to fight evenly for a little while with an enraged spiritual entity who was capable of affecting an entire mansion while dormant.
Physical: In Episode 19 (Usagi is Thrilled! Tuxedo Mask's Love Letter!) Tuxedo Kamen manages to support the weight of both himself and Sailor Moon while gripping to a narrow ledge showing some good arm strength. Holds this position for a while showing some good stamina as well.
Movement: In episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!) Tuxedo Kamen easily dodges the youma Tesuni's fireball and later when one of the fireballs was about to hit Sailor Moon he swoops in last-second style to save her. He shows good speed even in civilian form as in episode 15 (Usagi is Frantic! Rei's First Date!) he manages to save Luna from being crushed by a speeding truck while in civilian form.
Attacks: Tuxedo Kamen shows that his roses are in fact magical. In episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!) a rose disrupts all of the youma Tesuni's telekinesis and later in that episode the rose (apparently powered by posistive energy and thus attracted to negative energy) hits the youma in the face and even the youma with all it's strength couldn't get if off.
In the same episode Tuxedo Kamen shows that he has a cane which can magically extend several meters easily and that he can use with great speed.
Other Powers: Tuxedo Kamen is shown to possess a limited clairvoyance. In episode 15 (Usagi is Frantic! Rei's First Date!) Tuxedo Kamen senses that Sailor Moon is in danger. Later in episode 18 (Shingo's Innocent Love! A Sorrowful French Doll!) when he passes Nephrite (both of them were in civilian disguise) he senses Nephrite's evil presence. Strangely Sailor Mars (who was also in civilian form) despite being there as well didn't notice it which may mean Tuxedo Kamen's ability to sense evil is even more acute then Sailor Mars's ability to sense evil.
Besides that in episode 19 (Usagi is Thrilled! Tuxedo Mask's Love Letter!) when we see Tuxedo Kamen transform for the first time it shows that he unleashes a large amount of positive energy just from transforming.
Nephrite was supposedly stronger then Jadeite and he does indeed show many of Jadeite's abilities as well as a few abilities of his own.
Physical: Nephrite was a rather strong being. He was far stronger then the Senshi, in episode 21 (Protect the Children's Dreams! Friendship Linked by Anime!) where he proves far physically stronger then Sailor Mercury. He is also much stronger then youma, in episode 23 (Wish Upon a Shooting Star! Naru's Pure Love!) he casually tosses the youma Yasha far into the air. In the next episode (Naru's Cry! Nephrite Dies for Love!) he knocks two of the three plant sisters uncouncious by punching them.
He was even more durable then he was strong. In episode 22 (Romance Under the Moon! Usagi's First Kiss!) he easily resists the Fire Soul. However we don't see the full extent of his durability until episode 24 (Naru's Cry! Nephrite Dies for Love!) he first easily resist supersonic waves from the Plant Sisters. After that he is hit with, in order, having a handful of minature room-level explosions thrown at him, being stabbed through the chest with massive thorns, being horribly electrocuted, having all his energy drained and then being hit with a large room-level explosion. And he survives all this, if barely.
Mental: Nephrite was a very intelligent general. He was able to track the movements of all the stars in the universe at once and used the astrological meaning of these to divine the future, although he kept messing up the interpretation of them so it is not flawless clairvoyance, however with PIS off it should allow him to know most of his opponent's capabilities.
He also had the abilitiy to ask the stars for immense knowledge which he would actually receive. However this requires him to be in a specific area and takes time so it is impractical in a battle.
Movement: Nephrite keeps up the proud Anime Sailor Moon tradition of being really vague about movement speed, although as seen in episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!) he can move faster then the eye and has no problems keeping up with the other characters.
However he also has other ways of getting around. As shown in episode 21 (Protect the Children's Dreams! Friendship Linked by Anime!) he can superjump, even in civilian form, and uses it well against his enemies such as when he uses it against Sailor Mercury. Like Jadeite he can also teleport. In the same episode he displays teleportation through Black Holes like Jadeite did. He also shows other forms of teleportation. In episode 22 (Romance Under the Moon! Usagi's First Kiss!) Nephrite twice shows the ability to teleport in the form of light particles. Later in episode 24 (Naru's Cry! Nephrite Dies for Love!) he shows the ability to teleport as light partices with a gust of wind surrounding the light particles to knock around anyone who might be around and can use this ability in combat. Besides this he also displays the ability to levitate in episode 19 (Usagi is Thrilled! Tuxedo Mask's Love Letter!)
Nephrite also has very good reflexes. In the same episode he dodges the Sailor Moon Kick casually. In episode 22 (Romance Under the Moon! Usagi's First Kiss!) despite being blinded by the Bubble Spray Nephrite manages to dodge the Fire Soul. In episode 24 (Naru's Cry! Nephrite Dies for Love!) he manages to casually dodge the attacks of the Plant Sisters.
Attacks: While Nephrite dosen't fight himself often he shows more then capable when in one. In episode 23 (Wish Upon a Shooting Star! Naru's Pure Love!) Nephrite shoots an energy beam almost too fast for Sailor Moon too percieve that knocks her back several meters. After a few seconds of charging he calls down this energy beam to rain from the sky. This attack is spammable. Later in the fight he displays a far more powerful and much faster version called "Starlight Attack" with the one downside that it has to be charged for several seconds which keeps it from being spammed.
In the next episode (Naru's Cry! Nephrite Dies for Love!) Nephrite creates several large explosions in the street with a simple hand gesture. In the same episode he showed the ability to create fire from his hand and to have a sword. He shows his skill with the sword by using it to defeat the final Plant Sister.
Other Powers: Nephrite can enchant any object he touches with the spirit of a youma which takes over the person, turning them evil. As shown in episode 15 (Usagi is Frantic! Rei's First Date!) this can even work on clothing that the person is wearing which means it can effectively work on anyone in melee range without some kind of willpower resistence to it.
Nephrite shows increased senses during the arc. Even while disguised he can sense powerful auras which he does in episode 18 (Shingo's Innocent Love! A Sorrowful French Doll!) In episode 24 (Naru's Cry! Nephrite Dies for Love!) he hears Naru's cry from across the city and later in that episode displays a danger sense when he pushes Naru out of the way of the giant thorn the plant sister threw at her.
Like Jadeite, Nephrite is adept at making illusions. In episode 19 (Usagi is Thrilled! Tuxedo Mask's Love Letter!) he creates an illusion of dozens of himself and in episode 24 (Naru's Cry! Nephrite Dies for Love!) he creates a city-block (at least) level illusion of warped gravity and distorted spacial perceptions. Also like Jadeite, Nephrite has the ability to take energy from humans which he demonstrates in episode 19 (Usagi is Thrilled! Tuxedo Mask's Love Letter!) where he conjures energy-draining lightning to take vast amounts of energy at once.
Unlike Jadeite, Nephrite displays the ability to create matter from nothing. In the same episode he casually turn the constellation Leo into the mosnter Regulus and can do this with any constellation. In episode 23 (Wish Upon a Shooting Star! Naru's Pure Love!) he creates the dark crystal, an object that can supposedly track down the Silver Crystal, through sheer willpower.
Besides this Nephrite has the ability to remove a piece of his soul, known as the Soul Shadow to do his bidding (all of the Soul's Shadows abilities are in episode 22 Romance Under the Moon! Usagi's First Kiss!). The Soul Shadow can act independently of Nephrite. It can and usually does possesses a human and can move from one human to another leaving the first one uncouncious. It is rather quick as it can use dark energy to fly faster then the Senshi can run. If forced to go on the offensive it can shoot out dark energy waves the drained a whole ballroom full of people of their energy at once and paralyzed the Senshi. It also resisted the magic ofuda although it was forced out of it's current host's body.
Tesuni is from episode 14 (A Powerful New Enemy! Nephrite's Evil Crest!)
Movement: Moves about on the level of Sailor Moon.
Attacks: With her tennis racket she can shoot dark energy balls which trap people inside giant tennis balls. She can also call-up fireballs and can spam them as well.
Other Powers: Able to materialize a tennis racket made out of fire from nowhere. Can also telekinetically throw around people trapped in tennis balls.
Petasos comes from episode 15 (Usagi is Frantic! Rei's First Date!)
Attacks: Petasos has a hand attack called Handflower which shoots out a pod that entangles people. Shealso has a two-hand variant. She also has a similar attack using her hair called Petasos Ropes, which uses her vinelike hair to entangle her foes.
Other Powers: Petasos has control over magical butterflies which can short-circut electronics. She claims to have control over all animals and demonstrates the ability to have every squirrel in the forest attack at once.
Black Widow comes from episode episode 16 (Dream of a White Wedding Dress! Usagi Becomes a Bride!)
Movement: Due to having 4X the number of legs she was shown to move 4X the speed of the Senshi.
Attacks: Can very quickly shoot out an entangling web like a spider. She can also presumbably bite like a spider although it is unknown if the bite would be posionous.
Other Powers: Can see very far away due to her 8 spiderlike eyes.
Kyameran comes from epiosde 17 (Is Usagi a Model? The Focus of the Monster Camera!)
Movement: Keeps up with Sailor Moon who if I may remind you was dodging flashes of light earlier that episode.
Attacks: Shoots a flash of light from her hand faster then the flash of light from a camera that traps whoever it hits in a photograph.
Other Powers: Kyameran can create a personal forcefield powerful enough to ward off Sailor Mars's magical ofuda.
Jumeau comes from episode 18 (Shingo's Innocent Love! A Sorrowful French Doll!).
Physical: Is strong enough to crush solid paper mache! Just kidding although besides crushing paper mache she also displayed the ability to crush human bones, which is marginally better.
Mental: Can knock people back through sheer willpower.
Movement: Can Fly
Attacks: Can telekinetically throw her detached limbs at her opponents which according to Sailor Mars "cut like knives!"
Other Powers: Jumeau can change herself into dolls and telepathically control dolls. She has also shown the ability to detach her limbs at will to telekinetically throw at her opponent, she can easily regenerate her limbs so she has no qualms about doing this. She retains complete control over her detached limbs such as when she tried to choke Sailor Moon with her detached hands. Her only weak point is the small point on the shin of her right leg.
Castor and Pollux
Castor and Pollux are a dual youma, connected to perform the same tasks. They come from episode 21 (Protect the Dreams! Friendship Linked by Anime!) and are according to Nephrite "his best youma"although they are not promoted youma like Thetis was.
Physical: Shown to be stronger and more durable then the Senshi.
Movement: Matched the Senshi in terms of Speed.
Attacks: Castor can perform Fire Soul like Sailor Mars and Pollux can perform Bubble Spray like Sailor Mercury. Both of these were shown to outmatch the Senshi's versions.
Note: In the actual episode their in-fighting caused their downfall. However in a fight scenario with PIS off they will not normally do this.
Yasha comes from epiosde 23 (Wish Upon a Shooting Star! Naru's Pure Love!) although Yasha is actually under the service of Zoicite (the third Shitennou). Since she appears during the Nephrite arc she is listed here though.
Physical: Was able to melee evenly with Nephrite for a little bit.
Movement: Yasha has a startling amount of forms of movement for a youma. Like most of her peers she can levitate. However when she attacks Nephrite she displays the ability to superleap. Besides that she leaves the presence of Zoicite through apparent teleportation.
Attacks: Can turn her horns into minature drills apparently powerful enough to hurt Nephrite.
The Plant Sisters appear in episode 24 (Naru's Cry! Nephrite Dies for Love!) where they also appear under the service of Zoicite. They are more powerful then the average youma but still not on the likes of a promoted youma or a Shitennou.
Physical: The Plant Sisters have a negative energy forcefield around them constantly that can only be broken down with suffiecient positive or negative energy.
Mental: Are noticably smarter then the average youma.
Movement: Can Levitate
Attacks: Each of the Plant Sisters has a unique attack:
Housenka (the one with blond hair) can stretch her limbs and uses her extending claws to melee.
Grape (the one with purple/red hair) has tiny compart red orbs each of which,when thrown, create a room-level explosion like a grenade.
Suzuran (the one with dark blue hair) can shoot out hypersonic waves.
Other Powers: The Plant Sisters can cause plants to grow at a very fast rate using their powers to quickly overrun a small building with vines.