So, if a Pokemon holding a metronome hits itself in confusion twice in a row (assuming we click the same move both of time), will the damage be boosted?
If the Pokémon is switched out, uses a different move, or uses the move unsuccessfully (such as targeting into Protect or into an immunity), the bonus is reset to 0%.
Confusion (Japanese: 混乱 confusion) is a volatile status condition that causes a Pokémon to sometimes damage itself in its confusion instead of executing a move.
Confusion is something that prevents the Pokémon from executing their move, therefore resetting the bonus. This means Confusion won’t be boosted. Hope this helped!
Metrenome
Confusion