Continuous tormenting! Top swap gives a sense of inevitability here. Each turn, an opponent can torment opponents. It's not an effect strong enough to win on its own, but given time it can add up.

This is identical to the "torment" mini-effect of Hour of Devastation, like Torment of Hailfire.

Seeking how much this should fairly cost, and how much Top Swap adds to that. Torment of Venom does this effect at , but is also a targeted removal spell.