Artifact
If you de-activated an Evil Idol to activate this artifact, or there is currently an Evil Idol in play, then your opponents have until your next turn to either de-activate those idols or negate/discard Fiery Furnace.
If they do not, then at the beginning of your next turn all opponents' heroes in territory must individually choose to convert to crimson evil characters or be discarded.
"But whoever does not fall down and worship shall immediately be cast into the midst of a furnace of blazing fire." Daniel 3:6
