Remain in Battle Screen After Killing All Enemies?

I'm attempting to update the AI battle in Terra's flashback at the beginning where she fights the three soldiers, to change it from her attacking one with a Fire Beam to all three with a Fire spell.  I've successfully adjusted her AI script to hit all three with the Fire spell, however killing all three completely skips Kefka's dialogue bit and proceeds directly to the next scene.  Right now I'm getting around this by replacing one of the three soldiers with a lookalike enemy with higher HP so she doesn't kill it, but ideally I'd like her to kill all three and still trigger Kefka's dialogue event.  In areas like the Veldt when you kill all the enemies it remains in the battle screen for Gau's appearance event, so I was wondering if the same thing was possible here.  I've been searching around the Veldt events and haven't yet been able to find what differentiates them to allow this.