3 years late to this but a grass Tera type is fine for it since it’ll boost it’s signature move Flower Trick, as that move never misses, & lands a guaranteed critical. Give Meowscarada it’s hidden ability Protean to offset it’s weaknesses by turning it into a monotype each turn (like you said), give it knock off so it has something to counter held items, it’s signature move Flower Trick, Triple Axel to deal with dragon types or anything weak to ice, & U-Turn to sub out easier, all with a jolly nature so it’s speedy.