Hi all, I want to use my sorc for key running only. This means countess/summoner/nihl

I'm looking for a build that can deal with all the possible immunities (except for countess maybe, my merc can kill her) and some gear that can help me with nihl's corpse explosion and his vipers.
Last ladder i had a light sorc, wich could do with ease countess and summoner, but had trouble with nihl. I always had to use full rej, and against vipers i had to tele very fastly, because 1 hit meant death for my merc, and then death for me.

Any specific setup for nihl and vipers?
And best skills for these runs, assuming i can't afford an infinity?

Thanks in advance
Sunset