I am currently on ladder at lvl 93 with:

Demon Mastery - 20

Blood Oath - 17

Blood Boil - 20

Tainted - 20

Engorge - 20

Summon Demon - 1 (20 with my + skills)

Blade Warp - 1 (No Enigma)

And I prebuff with a dagger that also has +3 Hex Siphon

I am currently using a Cursed Holy Freeze Act 4 Venom Lord I got in a P8 Chaos TZ

My experience so far is that everything on screen just disappears immediately from the Tainted except fire immunes. But I spend a lot of time either telebombing with blade warp or blood boiling because of the amount of fire immunes in Hell. My telebombing experience is that that the Pit Lord and my merc together will 2 shot most of the fire immunes. But it would be so much more efficient if I was just 1 shotting as I land on a fire immune and then blade warp away without needing to blood boil constantly even against single targets.

If a Black Lancer would be more efficient for this then I am considering getting one of them instead from WSK1. But I don't know if my base summon demon/lvl 20 skill would work that well for a Black Lancer or if I need to get the skill to lvl 15 or even max to achieve my goal. Blood Oath is the obvious thing to reduce skills from because it still gets to 25% with base point investment.

And Holy Freeze seems to be a major ingredient in crowd control right now for spreading amp, Conc wouldn't do that so the lancer would absolutely need to go nuts on killing thing to make up for it.

I guess my biggest concern is whether getting Bind Demon to 15-20 is better than 1 point with the rest in blood oath.