Sombra decides to write a small book on all his greatest spells to see if ponies can replicate his magical might. Celestia and Luna know about it, but can't exactly do a lot about it, and you'll see why with the crazy spells he writes down.
Discord is supposed to always keep an eye on him, and that also means you! these are spells you can possibly use in your own stories, which is rather fun.

I actually wanted an excuse to write down a bunch of spells that other people can use, but i'm not sure i can do that so, i just had it as Sombra writing it. why Sombra? he's one of my fav characters so, might as well.