If people want feats for Allusis, fine. He was probably one of the Order's greatest Masters seeing as he was leading the Republic's finest troops/Order's finest Jedi Knights into battle at Bothawui. He survived until the end, and seeing as the battle was almost like Geonosis, we can assume that he's a pretty skilled warrior (in blaster bolt deflection, at the very least, but this probably translates somewhat into blade-to-blade combat). In the battle, he demonstrated a Protection Bubble/Barrier that could repel blaster bolts, and he erected that at the same time as displacing earth/knocking back enemy troops with telekinesis.
No, it just says his forces outdamaged the enemy like twenty-to-one or something. They ended up inflicting comparable casualties despite being outnumbered, so the battle ended up being a stalemate/Pyrrhic victory for the Empire, but a moral victory for the Republic. That's not overly surprising, though, since Gnost-Dural states it was several thousand of the strongest Republic troopers and several dozen of the Order's finest Jedi Knights that went into battle under Allusis' command, which would suggest Allusis was very skilled and powerful himself. He also survived until that last stand moment, so yeah, he's pretty good. Not sure where I rank him, though.