Talk:Battlefield of the Waning Moon/@comment-70.68.234.152-20161006175258/@comment-35019468-20161006184739

Iona's effect states, "Your opponent's SIGNI must attack if able." If you don't pay the ener, they aren't able to attack. The opponent is not forced to pay the ener to attack. They may either choose to not pay the ener, preventing their SIGNI from attacking, or pay the ener, causing their SIGNI to attack.