I'm a big fan of the Secret Rendezvous card, which has four different versions of the Golden Saucer date scene from Final Fantasy 7 with each potential date: Aerith, Tifa, Yuffie, and Barret
Satoru Umezawa could slot in there, too, but is probably even stronger as a commander, offering a way to drop a Blightsteel Colossus into play with minimal effort
The most famous example of an undead boss that can be defeated this way is Gi Nattak from Final Fantasy VII
Its unlikely that youll even play Gush in the early game, as your lands will be best spent tapping for mana each turn
Bruni Fire Salamander is the best backup
And if you trade up for a big force that's a win for you as you'll end a massive threat and then you'll net the death trigger