[UninspiredName]

This one wouldn't be too hard to implement, and would open up monster modding incredibly.

#spelleffect <timing> "<spellname>"

Timing would determine when the spell effect would be triggered. 0 for at the start of a battle, 1 for every turn, 2 for every time an enemy is hit, 3 for every time an enemy is attacked, and 4 for when the unit dies. Spellname is self-explanatory. One could restrict them to a non-existant nation to stop the effects appearing on the spell list. This would let us do anything from shuten-doji, to suicide bombers, to whatever the heck the darkness-shrouded Lanka summons are called.