The "then" ruling was wrong, you can activate the second part of Megadeth even if you can't suspend an opponent's digimon. "■Effects Divided With “Then” Some effects read, “. Then, ,” effectively splitting themselves into multiple parts. When activating effects like these, first perform , then perform . You can activate these effects even if you can only activate half or none of the parts. It is also possible to meet conditions for “” by performing “”."
The Davis digivolve effect also happens on the declaration of the attack, so you would've had a 15k Imperial on the attack as well, not just after the attack
Good shout! Ofc, that doesn't prevent digimon from using specific/preferred pronouns or identifying one way or another, but nice reminder for one of my favorite lore tidbits.
