This one only cropped up in the challenge battle after the game ends. If a regenerating creature delays, it receives its regen twice:
1. Regen critter's init comes up. It regenerates X hp.
2. Regenerating creature decides what to do. Let us suppose it decides to delay.
3. Critter's init is reset to the end of the current round's init order.
4. Regen critter's init comes up at the end of the round. It regenerates X hp again.
5. Critter now acts.
So delaying allows a regenerating creature to regen its hp twice.
If this bug is a tricky fix, I'd say leave it (regenerating creatures don't tend to delay in the regular game) and fix for KotC 2.
