i tried many times now..
but something went wrong every time, i kill the enemies to slow, they surround me, and i die...
really need help to kill him...

any tips/help ?

Which guy do you need help with?

Zurvan, the last one in this mission

Oh ok. So what I did was. Just attack him and dodge the aoe (red lines). When he spawns monsters, use the "wave" move, the one that makes you fly forward and do damage in a line. Then do heal. If he spawns the ultras~ use the warp strike move that does big damage. And keep healing, there's no enrage timer. If things go really bad, you can burrow to regen some energy but you shouldn't need to.

Can always save hop. Save whenever you're full HP and no mobs are up

maybe Psy's brutal walkthrough can help you
http://www.youtube.com/watch?v=cln_xCsg0Vc

didn't watch it though

If this 'Zurvan' is that big zerg that spawns a million banelings, I soloed him

Had to solo this guy for the 500 kills achievement (Kerri getting 500 kills in the whole mission) and I would move hit and move a bunch, then when the banelings spawn I'd try lining them up then use the wave move.
After I got my 500 kills my army (which was at the entrance of the area just chillin) moved in and helped me finish off the boss