Wu Lizhi has maxed out his skill points in both causing trouble and getting into trouble. He transmigrates into the familiar world of anime, and then... the original plot goes so far off the rails that nobody recognizes it anymore, including the protagonist himself.
"So, what's going on here?" In the Sword Art Online world, Wu Lizhi looks at a doge farming minions in a field, Maple shouting, "Stand behind Braum!", Yui thinking she's a murderer... Faced with all these bizarre developments, he can't help but ask in confusion.
Wu Lizhi, from many years in the future, sits on the sofa and reminisces about his accomplishments in other worlds. He says that his past self was too young. Now, nothing can surprise him...
(Confirmed worlds: Sword Art Online (ongoing) - Re:Zero - Type-Moon)
(Unconfirmed worlds: Puella Magi Madoka Magica, No Game No Life: Zero, Haiyore! Nyaruko-san, Overlord, The Hero Is Overpowered but Overly Cautious...)
(The main world is the Cthulhu Mythos world. Before Wu Lizhi starts transmigrating to the next world, he has to go back once.)