Most useful item in TQIT

[greatcthulhu]

I'd have to vote for the Ritual Beads/Amulet/etc.

I've been carrying these things around since TQ and just haven't used them. I've found versions for levels 11, 15, 21, 28, 40, 43, and 47. Currently my Haruspex is using:

RITUAL BEADS OF MIGHT (green)

+61 Strength
+137% Life Leech resistance
+17 damage to Undead, Demons, Magiical
-24% dmage from Undead, Demons, Magical

Level: 47

Since I've replaced my Pendant of IMmortal Rage with these beads, I've haven't taken any significant damage and can survive runs in the Legendary Overlord's Passage (Even Toxeus hasn't killed me)--which is nice since the Chest in the OP seems to spit our more of the blue/purple/Formulae items than other chests.

[Zaishi]

Jewelry with that mod that reduces energy by a set amount (seen 23-35% so far) and converts it to damage (50% as damage or something). Put two or three on, and just destroy anything with energy. There's a lot of nasty casters, they go down in one hit easy with these things, even heros.

Doesn't work as normal on bosses, but it still saps their energy really quickly.

[Infares]

It's probably subject to Energy Drain Resistance, so lowering blanket resists probably helps.

Additionally, Total Damage buffs probably increase that damage as well.