Creating Spells based off anime

[Briton]

So in the current campaign i'm helping run, people who die in the real world have a chance to come into a D&D-like world, with all their current memories. One of the PCs, a wizard, has gotten the idea of trying to make spells based off of anime/games/shows/etc. Heres a list of some things he'd like to try:

Kamehameha (Dragon Ball)
Mafuba (Dragon Ball)
Gaster Blaster (Undertale)
Luffy's Gear Second (One Piece)
Skyscraper (or babel tower, not sure which its called) (Fairy Tail)

Anywho, my question is has anyone done something like this before, creating spells based off of other forms of media? Is there a method to doing this?

[Ganymede]

This is actually pretty easy to do.

First, decide what spell level would be thematically approptiate for the power. Is this power a minor trick or something only mastered with lots of training?

Then decide the effect the spell should have. Is it single target? An AOE? Does it do damage over time or have a rider?

Finally, find a spell of that level that matches and swap out the damage type and/or riders for something more appropriate.