It doesn't become available. It's a dummy skill that Cecilia doesn't learn naturally. It's literally just text and the description when you cast it, it doesn't call any common event or anything - targets one enemy and does nothing. (It's also highlighted outside of battle since it's set to always be usable.)
There's no point in leveling past 25 at the time. If you don't know how to save edit or modify JSON and JavaScript to mod stuff you want in or out, you shouldn't either because the way RMMV default skill learning works, you'll become unable to learn skills if your level is higher than the level the skill is learnt at without level draining yourself.