Also remember that death in 7 turns would be much slower then anything Ferox (a comparable FG, without PC or CC aswell) would be able to pull off!
I still really like the idea and theme, but I think he needs to be toughened up a bit.
How about making him a trio with light. That would give him acces to blessing (blessed wardens) and sanctuary (to make him a healing monster).
This doesn't really fit the theme, but would make him alot tougher.