My least favorite MU.
Heres what Ive learned from playing my bros Wario
All of his aerials are beastly. His Fair is fast and combos into serveral. He can chain 2-3 offstage and then edgeguard the barrel. The aerial he spams the most along with his Dair. His Dair combos, has multiple hits and a long duration. His Bair is good from ledge hops for edgeguarding. And his Uair has crazy priority. IIRC, its hitbox extends past his hands so dont expect to beat it with a Fair when your above him. His rising FH aerials can put a lot of pressure on you if you just sit in your shield; he can do falling Bites, Dair behind you, space Fairs, or even just AD down to grab. He has some crazy aerial movement so dont ever try to shield grab. Youll just get punished.
The bike can be annoying when he leaves it on the stage since he can just camp behind it with weaving aerials. As ADHD said, you can throw a banana to make it bounce like on Brinstar but be careful: the Wario can just catch it off the bike and you will have lost a banana. What I like to do is Fair him which outprioritizes most if not all of his aerials. Then try to get and keep him offstage which shouldnt be that difficult without his bike.
Try to keep control of the stage because once he gets you offstage, he has several options. He can Waft you, Fair/Bair you back out or even both (Fair to Waft is supposedly an awesome setup offstage and practically inescapeable even if its expected
) You should also keep in mind that Wario can instant wipeout his Bike on the edge and then throw it back out creating a Wall in front of the ledge. You really have to mix it up when you recovery or youll just eat a Waft or get gimped.
To keep control of the stage, use careful banana placement. I usually keep one in front and one in hand. If he hits your shield when you have a banana, GT towards him and downwards; this will allow you to follow up as if you had GTed towards him. Once you trip him (which wont be often) take control. I believe this is one of those matchs where you do the most damage after one trip (like the Olimar MU). Be aggresive and dont let him gain back control. Combo him. Just dont be stupid or or youll eat a well timed Fair or AD resetting the stiuation.
Finally, if you ever get the double banana lock, do not smash him. Instead grab him over the ledge and then mix it up between a SH Dair and Fair after the grab release so that he doesnt know which way to DI. And if you can, learn to single naner lock him to grab (like Im doing.) Once you can, the Wario should be scared to approch while you have a banana inhand for fear of hitting your shield with a mistimed aerial and allowing you to follow up with the SNL to kill. At least thats how my bro felt after I did it to him once