DACUS and his amazing aerial mobility. the waft, shoulder bash setups and the distance you get from jumping in shoulder bash, sweet and sour spots of his moves, edge guarding.
wario mind games are too real.
cool tricks:
if you hold uptaunt during his dair the fart animation for waft comes out. it doesn't always catch people off guard but it usually does at first.
Wario's dash grab is super important to learn i think. Its amazing for catching opponents off guard and can lead to a good combos or even a stock depending on character/stage/throw. its also great for mixups. dash grab > back throw > shoulder bash is amazing if they don't tech correctly lol.