Probably should have asked this before I bought 6 packs of these lol.

The card ability says when you take damage that's equal to your health total. But if you take damage that exceeds your health total, would that not trigger your ability?

You can't take more damage than your health total. The rest is ignored.

Damage, RRG:

· A figure cannot suffer damage in excess of its Health. Any damage over
this amount has no effect.

Also note that Parting Shot does not say damage you suffer from an attack. It says when the figure has suffered damage equal to its Health, before being defeated. The former is any additional damage from the attack, while the latter is the total damage the figure has at that moment.