I think Wario is a reliable but simple character. In head-to-head battles, wairo don't fear anyone. But he don't have a magnificent style(like joker or ZSS), his only magic is waft(which could be shielded and dodged)
For me, I don't fear sword characters, but weird,quckily movements are fatal to me. DIDIKONG's banana skin, Snake's grenade, Ness's erratic airattacks would make me feel terrible. Wario‘s range is not good, so he may not adapt opponent's changeable strategy.
I like wario because I think he is a cute and funny man. Big hands, big mouse, pink pants and funny waft......always make me feel easy and relaxed. Many people say he is not good-looking......so I am happy to see you guys are willing to pay attention on wario.
And......please forgive me for my bad English......