Don't forget that if you control 2 Thunderbreaks, each one will trigger anytime any dragon you control gets targeted by an opponent!
Tag: Thunderbreak Regent
Thunderbreak Regent only triggers for Dragon permanents.
Thunderbreak Regent's ability is powerful, but don't get carried away. It only works while the Regent is on the battlefield, and it only triggers when an opponent targets one of your dragon permanents (on the battlefield). It doesn't work for dragon spells on the stack or dragon cards in the graveyard.