Basically the joke is that Mario says how much he enjoys to partake in ssbu even though there are some problems with. and he demonstrates this by saying he hopes he doesn't get matched with Sonic on wifi, (which is supposed to mean online) and then a buff sonic appears even though mario just said he doesn't want to see sonic online, cause fighting Sonic online is really hard cause since the game mostly lags all the time and since sonic is really fast, fighting him will be a problem because of his fast speed on a laggy game, and a lot of people play as sonic so its common to come across a Sonic.
