Illegal Swadloon - Hard mode Nora

Nora's Swadloon has the move X-Scissor when you fight her at Metchi town on hard mode. Neither Swadloon nor Sewaddle can learn X-Scissor legally in any format. Not as an egg, or tutor or transfer etc.

Swadloon can learn bug bite. That could be it's substitute as far as legal physical bug moves go.