Well, I might have tricked the game by W-ing a Quadra'd master with Hades and KOTR, bypassing the usual check.

In any case, the major point of my setup was to cast Hades 4X (to make sure that one of the four casts hits Ruby and not the tentacles) THEN KOTR, ensuring Ruby never gets a chance to attack, and if it does, it's not happy, because it takes another 4XHades/ KOTR and I'm back at full. It's a process that can be executed completely passively after the first input.