I don't know if anyone else has had this problem, but I have noticed this in Mooshu, not anywhere else. It might be a bug, but I'm not sure. I was battling some corrupted earth spirit's when I noticed that one of them casted a seraph spell, which is four pips, with three pips. Bt after that, it was left with one pip! So that meant that the spell only costed him two pips, instead of four! I've noticed this a few times in Mooshu, but only in Mooshu, nowhere else. Please let me know if you've had the same problem and what this might be! Thanks -Madison Silverblade
Some enemies cast special versions of spells that don't cost as many pips as those used by wizards. These spells also generally don't do as much damage as the regular versions do.
