Help needed :Merc Equipment

Heyy.....

I am using Hone Sundan for for my merc.I have a treachery and a vampire gaze also for my merc.So I have already reached the 37% break point.Do I still use the famous shael/shael/amn to reach the next breakpoint(or rather would I reach the next bp)?I also have a Guilamme's face.So, Iam a bit confused with the set up I have to give to my merc.

I am playing with a poison necro in SP hardcore,so do I put on gaze to run pits and meph(Can a poison necro take meph quickly?)with guillame's to have the best cb?

Thanks in advance...