Have JOR, 4 megrims, and the altar out, play panoptic mirror, imprint
cauldron haze on it. Play Abyssal Horror.
Wait one turn, then activate panoptic to give it persist, sacrifice it to the altar,
it comes back, JOR removes the -1/-1, sacrifice again. You mill them out, JOR
buffs to infinite/infinite, they take 8x the number of cards in their hand, and abyssal horror's ability activates and infinite number of times.

 


You can skip the panoptic part, but it lets you
run the combo every turn, not just one.