[quote=@ERode]
So how is Magic Power calculated when one doesn’t have any like, magic skills to begin with?
[/quote]

Basically, while there aren't a bunch of stats and dice rolling like in a tabletop game or regular RPG, I've sort of got this arbitrary system running in the background. As players test their limits with different skills, get into fights, etc I'll let them know when they're "running low on MP" or "HP is decreasing over time," and so forth. It's just a "soft magic" form of the usual Isekai Numbers Game in an RPGverse. If you'd like a more detailed explanation to start with, for a "constant" spell like Frost Arc, I imagine at this level a thirty second continuous application would drain all the MP Esfir has. Within that thirty seconds though, it'd be like exposing an enemy to a relatively severe ice storm.