Originally Posted by
Curmudgeon
Without divination magic or some other way of determining whether an apparent creature is actually a figment, the description of Mirror Image requires that Cleave functions identically, to your sight and hearing, with those figments. If you had Cleave and your weapon behaved differently when destroying an apparent creature vs. destroying an actual creature, you would be violating the above requirement of Mirror Image. Only a detection means other than vision or hearing, such as divination magic, would allow a difference. Lacking some such other sense, the observing warrior with Cleave must see and hear the same effect on their weapon after dropping a figment and after dropping the spellcaster; that is, the weapon will Cleave through to attack another target in reach.