@Shadowchaos: Yeah, I apologize for that. The game is similarly vague using terms like "small" "moderate" "large" "severe" and "massive" to describe how much damage is done.
There are skills that deal physical, fire, ice, electricity, wind, light, dark, or almighty damage. They can be single target or hit all enemies but never allies. Or the characters can just bash an opponent with their weapon of choice.
Light and dark skills are both instant kill, though they have between a 30-60% chance to hit depending on the skill level and whether it's single or multiple target. Most other skills have somewhere between 95-98% chance to hit.
Now for unique skills. It was surprisingly difficult to find the third tier persona skills. Chie, Naoto, Kanji, Yukiko, Yosuke, Teddie, Rise. They also get skills by Social Linking. Those are here. Just scroll down until you see the yellow grid. Chie, Naoto, Kanji, Yukiko, Yosuke, Teddie, Rise
You know, the more I look into this, the more I realize that there is no simple way to quantify what they can actually do. I haven't actually played P4 Arena, so I can't give much info from there. In the RPG the fights take place in an abstract area that doesn't take any sort of damage, and the things they fight are Shadows from Jungian psychology so I don't even know where to start on them. Maybe they'll never get a battle.
@takashichea: RWBY is a fun show and Monty's a great animator. It deserves more love. I can't wait for the Vytal Tournament.