My "LV10 Horus" idea is a lot more challenging than I thought it would be. Horus LV8 is already pretty strong on its own with it's infinite spell negates. I honestly have no idea how to go up from there without it being game-breaking. Maybe give it the ability to negate any card activation but with a discard for cost? I'm also not sure what the Atk/Def would look like, apart from maybe something like 3200/2000 or something along those lines.