hey, OP. had an idea for an animation I thought i'd run past you.

Explosive Decapitation (referencing Cock of Steel, >>6282)
Dark Superman captures a rebel to his rule (Supergirl, Wonder Woman, etc.) and makes an example of the traitor. he neck/chin fucks her, snuffs her and when he cums, his Kryptonian ejaculation blows her head clean off.