What ability is this, and what class uses it?

[Abriael]

And we all know the shitstorm that caused, and yet people here are going nuts FOR an auto-attack.

Yep. I actually *liked* that combat system by the way. It was pretty tactical if used in it's deepest options, but i would definitely have quite a lot of trouble even figuring out how to apply even parts of it to a MMO.