Talking sword? Sure. Talking horses? Bit weird, but okay. Hunters after my head? That's a bit different. So much for the vaunted love and tolerance of the ponies.
Most people wouldn't think dressing up as an optional boss would land them in Equestria. Most people would be right. Most people aren't me. Most people still have their bloody head!
What would you do, if your world inadvertently changed around you, and you were marked as a villain? Inventions are created by necessity, creativity, and chance. So an Invention was made in more ways than one.
Defating foes from Beyond? Easy enough. Making Celly see where her mistakes lie? No problem. Being torn apart and reborn because of the Golden Sun? Okay, that one, I admit, knocked me for a loop.
Due to how annoying it is to be defeated, an affably evil lich decides to give up the evil business and just wile his days away doing absolutely nothing. The good guys don't really see this.
Okay, saving Equestria from powers I foisted on it, not a problem. Saving a mare from certain death, easy! Getting used to being a pony? Someone shoot me.