Also remember that each spell has different coefficients of return for life steal or life on hit. some get horrible returns (cough blizzard) and some get great returns (DH traps) and most fall in between. This is especially true for AoE spells since they are designed to hit multiple mobs and I still haven't read anywhere what the "ideal" number is for everything to line up.
Life Steal has no coefficient aside from the reduction due to difficulty. If you do 100k damage with Spell A, you gain the same life as if you did 100k damage with Spell B. The only exceptions would be if a spell doesn't work with life steal, which hydra may not.
Also, the reported reflected damage is 10% of your damage done, which is further modified by armor and physical resistance. This means with 90% damage reduction you need 5% life steal to break even against a single target, after accounting for the reduction from Inferno. That sounds about right since I have 91% physical DR in Archon form, with 2.7+1.5 = 4.2% Life Steal plus almost 600 life per second regen and I gain life against 1 reflect damage mob. Expected life gain for 225k dps is 6057 life per second for single target, exected damage taken is 6075 damage per target.
side note horde, mortar, reflect, fast demonic tremors CAN GO TO FREAKING HELL SKREW YOU BLIZZARD AND THAT COMBO!
Fast is a little redundant, I think, since they're sped up as rares anyway, but I'm 100% with you on that. Damage Reflect Tremors are just horrible for Archon, same with Phasebeasts. With teleport and illiusionist, I can do decent against them though. I just teleport as soon as I get hit once and blast away, though with damage reflect it requires a lot of creative teleporting around health globes or I'll kill myself.
Any reflect damage mob with illusionist is fine by me, especially with LoK at or around 2500. Each illusion gives you life so bring them on. It's the extra health/reflect mobs that give me the most trouble.
I play monk and this combo is not working properly I think. This is my theory why:
I think reflect damage amount is triggered when you do damage to moster. If you do damage to one monster, its actually just 1/3 PerMonsterDamage and 2/3 PartyDamage. 2 other monsters lose their health too but because you havent directly damaged those(in that excact moment), reflect from those are not triggered. Now if you arcane beam through all monsters, reflect should work as before.
pretty sure if i used an arcane missile on 1 of them i would get 3 returns of reflect assuming that the ones that did not get hit directly had been in range. i think i am just going to go with i need more all/physical resist and just outgear it.