Opponent is targetting creature i control instead of their own. Spell does not resolve, but shouldn't be able to be cast like this in the first place.
#Airbenders Reversal wrong targeting
burnt dirge
meager girder
[[Airbender reversal]]
regal mapleBOT
Instant — Lesson
Choose one —
• Destroy target attacking creature.
• Airbend target creature you control. (Exile it. While it's exiled, its owner may cast it for 
rather than its mana cost.)
Aang employed the typical Airbender tactics against Zuko: avoid and evade.