Please add the ability to play against one's self in the game, local

We would if we could. It’s just not that easy to implement. Maybe one day using puzzle mode you could control both sides. You can also use manual mode like Dove already stated.

You can also just create two different discord accounts and duel each other. We prevented people from opening two Omegas to stop cheating in tournaments where you could easily register as two people and spectate your future matches.