I've got a pois/summon necro. He can do anything with ease except baal.
He's faster at pit-running than my faith/pride zon.
I usually do Pindle, Shenk, Eldritch, Pits, Meph and Diablo with him.
Timed it as well, average run is 12-15 min.
Recently got Infinity for merc, now he can do all of those with full mf on.
Infinity on necro oowns big timt as it also greatly reduces fire resist of enemies and therefor greatly increases the damage of corpse explosion in combination with amp dmg. If you assume amp ans infinity on an average hell monster, meaning 50% physical and fire res, you get them to -30 fire res and -50 phys res, resulting from 70-120, which would be halved to 35-60% of monster life, a wooping 98-168% dmg.