He can bring the dead (or nearly so) back to life.
He is a one-man weapon of mass destruction.
We've been promised masses of detonations (detonating the fleet).
Who in Trek canon fits the above conditions/descriptors?
Lazarus was capable of detonating two universes (what's a fleet compared to that?).
As such, Lazarus was the only "one-man weapon of mass destruction" encountered in canonical Trek.
Lazarus rose from the dead (whose to say he's not the same one from ancient times, eh, eh?).
It's not Mitchell, it's not Trelane, it's not Garth, it's not the Talosians, it's not Harry Mudd, it's not Cyrano Jones and it's certainly NOT Khan.
It's Lazarus. You heard it here, folks.