Come lv. 23 or 24, the Black Wizard can conjure up an enormously powerful force and fire it from his hands like friggin' Goku, obliterating his foes to eradicate Hit Points with a damage range of 250-450.

NUKE


But many hapless adventurers have wandered down the wrong corridor in the Sky Castle, and after taking a pre-emptive 300 damage smack, face a well aimed NUCLEAR

As far as I can tell, the damages are roughly the same, but the names are different. This implies that, somewhere, there is a nuance of difference between these two ultimate power spells of mass destruction.

What is the difference?