ReiKai (Level 9)

Actually her body wasn't combat-oriented, it was her training that made it so. The Imaginos cells can transform at her will into whtever she needs. She doesn't produce Plasma like the Berserker body did. She has to create the image of doing so in her mind and transform her body to create the organs that create plasma, and usually fires it from her fingers in the form of blades. Sechs (a pure cyborg/android created using Alita's battle data and was #6 of the AR-series, which stands for Alita Replica Series) can also create plasma with his new body, but it still takes control.
 
Alita could make plasma in the Imaginos 1.0 form before her upgrade and went into battle against Sachumodo whose output was at least 10x her own and they ended up creating a field of plasma which exceeded 100,000c, that's degrees celsius. 
 

Tifa Lockheart of FF7 beats Nina too. Handily. But all fall before Alita. She's too full of awesome and win.

Alita has the Imaginos body which is nanotech and designed to function like a living body (so she can eat an stuff), but she's still super-human and after an incident she evolved to Imaginos 2.0. She's not just some machine. She was originally human and for most of the series her brain was still real and fleshy. In Last Order it got switched with a brain chip without her knowledge, but I suspect that towards the end of the series she'll get her brain back and merge it with the brain chip and make herself even more ungodly powerful.

Again, no. Alita is a master of Panzer Kunst, the Ultimate Cyborg Martial Art, which was designed for both ground and zero-g combat. You want pure skill, Alita pwns that in spades. Her techniques combined with her cyborg body make her a beast in martial arts combat. One of Alita's basic attacks is the Hertza Haeon. It delivers a controlled vibration attack and kinetic energy, usually used to destroy the brain or heart by causing it to explode. It works just as well shattering body parts and easily dealt with most cyborgs this way. Even the slightest touch is enough for Alita to use this move. One touch and Nina is dead.

No, nina could not escape. Alita is high-hypersonic in terms of speed. Nina would be standing still next to how fast Alita can go. Alita was Supersonic early in the original series. Even Alita in her Scrapyard body would slaughter Nina. It's pretty much been noted that current Alita would solo the HST.

Nina gets rapestomped by Alita so effortlessly it's not funny. Alita takes on people whose punches pack more force than a nuke.

SoK killed God off his Throne, which is what made him Omnipotent (or semi really). It's weakass garbage. Setsuna Mudo in Angel Sanctuary killed God. Dante (Demon Lord Dante) beats God, who was nothing more than a giant alien energy being.

But then again, Darsh does have the Judas Pain and Dispel Bound which makes him incapable of simply "losing".

Tenchi Masaki. He's from Tenchi Muyo! He's the Avatar of Kami-Tenchi, TOAA of the Tenchi-verse. He has 6 Light Hawk Wings, any one of which can negate all offense and defense and erase you from existence to the point only he himself or a greater being can restore you. Tenchi nearly shattered the multiverse from having a mental breakdown when ascending to a higher plane of existence.

Try Spectre vs. Tenchi and we'll see which side wins

Yeah. Presence comes down and goes; "Alright Spectre, that's enough now, ya'hea? Ya had a little too much coke today. Time to settle down an relax."

Or Michael and Lucifer double-teaming him.

And yet got put down by Jobberseid who isn't even planet-busting. Yes, I hate DC for the most part, but that doesn't mean that Spectre doesn't suck as a cosmic deity.

would be nice to see the new series, and kinda disappointed that the .hack MMO was never given a world-wide release. Seems it was only ever produced and distributed in Eastern Asia and Japan (greedy bastards. I wanted to play it!)

The Presence is DCU's TOAA, who is always the writer at the time. DC's writers in general screw around a lot which is why the comics are so inconsistent in terms of power levels. DoV Spectre should be nigh-omnipotent and 2nd (3rd) only to the Presence itself. most other times he's only pictured around Skyfather level.

You can find the secret episode on youtube in 3 parts.

Piccolo solos the whole HST (Holy Shonen Trilogy; Naruto, Bleach, One Piece).

I have the .hack mangas as well, plus the novelized versions, and the anime series (sign, Roots, Liminality, Twilight Legend) and saw the secret final episode/ending of Roots/GU that was only ever shown in Japan after the completion of all 3 GU games.

That, again, still depends on the mood of the Presence. If the Presence is serious, like, completely serious about Spectre doing a job, Spectre will be pretty damn powerful and has kicked out galaxies in the process. If the Presence feels like being lazy, half-assed, or just feels like being a dick to the Spectre, Spectre's powers won't be so great and he'll get shit in his face a lot. His power levels are all over the place and inconsistent.

Not yet. I don't have a DS myself. Little bro does though, but he has no wireless connection for it to download anything. Will have to work on that. And yes, .hack is the shit. I have the GU trilogy and 3/4ths of the first .hack series (infection/mutation/quarantine) and plan on getting the final installment of that soon, just for the sake of having it. Despite the fact the controls in the infection series and gameplay are...suck compared to GU, it's still fun to have and get through.