>>43592742As of Gen VI, Egg moves and Event moves can be re-taught by the move maniac.
This means that giving a Pokemon access to Sketch through an Event would open it up to being able to use literally any set of moves, provided the move exists and isn't hard-coded to one Pokemon.
Going by that definition, this is probably the best Barbaracle set:
>Shell Smash>Fishious Rend>Power Whip or Horn Leech>Diamond Storm or Head SmashIf we're going by what OP probably intended (so just one new move), then just replace Liquidation on all of Barbaracle's sets with Fishious Rend.
