Xenosaga II: Random enemies kicking my butt.

I just finished the game. I have complaints about the voices, the new designs being unexpressive as hell, the fact that the Gnosis were shoved completely into the background and some other things. I did like the ending, especially the effect of that massive gate-out light framing chaos/Yeshua and the Movie Scene Soundtrack is pretty sweet.

I’m doing the post-game quests now but since I’m getting completely obliterated by the enemies in the yellow Forbidden Device, I’m thinking of doing some other stuff for a while. I need two things:

[li]A good place to level the E.S. I’m fighting the Crescens (I laughed when I saw them :P) on Omega System but I wanted to know if there is anything better with not-suicidal battles. All my machines are Level 38.
[/li][li]Some way to beat those enemies that you encounter on foot right before the room with Cathedral. The ones that look like a centaur, a giant and an angel. I can lower their HP, survive the explosion thingie with Safety Level (And KOS-MOS can even withstand it on her own) but there’s no way I can deal the 2000+ damage needed to kill it in the only turn it gives me before regenerating even with full Stock and Boost. I have thought about using Curse but that’s going to take a while to learn. My party is normally chaos/KOS-MOS/Shion.