Krisk, siphi, artak, mordecai, oboro (high resist to tank mischief), ??? (Block buffs anywhere in your roster?)

Mordecai is great in Hydra. I've been meaning to try Artak.

really need to see the rest of the roster here for Decay + Torment counters (other than Rector)

And Rector is really *not* a great Decay counter without buff extenders. You do happen to have Krisk, who'll help on that front, and his A2 may allow him to serve as a Mischief tank. I don't think there's room to run Siphi on that team too, you just lose too much other stuff.

I think you could possibly do something like:

• Krisk - HIGH res (300+), high speed (240+), other stats irrelevant
• Tatura - does her passive trigger taunting set? If it does, that'd be a neat setup.
• Rector - fast fast fast. Cycle as much as possible
• Artak - one of your damagers
• Gaius - your other damager (certainly not ideal, but probably the best you can manage)
• Siphi - I guess after looking it over you really have no better option for this spot