I’m on board with this actually.

Seems to me that distinct skills should have distinct names, while upgrades to II, III, IV etc. should instead of upgrades to distinct skills.
Stone I upgrades to Stone II, etc.

The fact that Fire, Fire II, Fire III and Fire IV all function completely differently… bugs me I guess.
Would make much more sense if Fire II was Fira, Fire III was Firaga, and Fire IV was Firaja.
It would allow for upgrades to these skills, so that we could get a superior Fira II to make our AoE rotation a bit smoother, instead of having a defunct Fire II.
And Fire could upgrade to Fire II to have a shorter cast time or something.