every time i try to kill him a Freaking insane special char. comes out and kill all my party members with one hit! any ideas/suggestions. i want to know what he has

You cant kill him without that bugger spawning in unless you've sided with Bodhi and are on a mission to destroy the Shadow Thieves.

SPOILER:
>
>
>
>
>
>
>
I do believe you are talking about the "immortal" version of A.G. who is wielding the "killer sword", at that stage he is too fast and cannot be killed. If you really want to kill Renal, side with Bodhi first and complete couple of quest for her (since you will confront the "mortal" version of A.K.). Apologies for the initials, I forgot his exact name.

im in chapter 7 (just doing it for fun. and yes he has some sort of "killer sword"

I couldnt kill Renal anyway- when I did the quest of clearing out the thieves guild Renal wasnt there.

If you want to ruin your game (or explore it), or just put yourself under A.G.'s hat for dealing average of 1000+ damage per hit, try the code "killsw01".

i sided with the Shadow Thieves in chapter 3 and they helped me kill Bodhi the second time