Is this the spell you created? I am almost certain that we already use the incantation "reverto" in the SSRPG as a counter to transfiguration spells, so if you can keep it, you might have to change the incantation to avoid confusion.

That is not to say that you can make them, though. Personally, I wouldn't mind it, but the wiki is intended to be SS-canon and spell creation tends to be exclusive to Staff members. If everyone could create spells then it would get a little... messy. I suppose it's just one of the perks of being a staff members. But I will poke Ern about this.

Doooooooooooooooo iiiiiiiiiiiiiiiiiiiiiiit.

Yes, you can. BUT, if there's already a school in the area you were thinking of creating one for, I strongly encourage you to just use the already existing ones. You don't have to, but his way it's a little less confusing, and much cooler because characters could have met abroad or studied abroad at the same schools and stuff. This is why when I created a school in Finland I wanted to keep the description basic so that others could jump in if their characters went there.

Here's a list of the existing ones for reference!