Theories
Theories are speculation about Five Nights at Wario's.
The Killer
Yoshi could have started it all but due to endless guilt and sadness from what he had done to everyone, he killed himself in the Garden, in which could be why he was outside in the Garden, looking into the Tool Storage sometimes as a ghost and stalking The Player. How Yoshi might have been killed is he that he kills himself.
The Killer might be Richard McRoy, it's possible he's the Phone Guy in the second game as he worked 6 nights in the first game, he locked the doors on Thomas Taylor (The player) to keep him from leaving on Saturday and Sunday possibly in an attempt to keep him from saying a word to the police, by sewing his mouth shut by letting the Plumbers attempt to kill him, at the end of the phone call on Night 6, his voice changes somewhat in audio, sounding a bit like Wario himself and even went into hiding from the police.
State of Theory: Richard is the killer, but not willingly.
The Wario Man Costume
The costume of Wario Man is stolen. It's possible that somebody is using the costume. Who this is, is Bruno Gate.
In Five Nights at Wario's 3 it was proof of a killer in the Wario Man Costume.
State of Theory: The man behind the Wario-Man costume is Bruno Gate.
Rumors
Rumors are a fake thing in a video game that is meant to be spread.
Wario Man jumpscare
There was a rumor that Wario Man had a jumpscare in Five Nights at Wario's. This was proven false because there is no Wario Man jumpscare in the game files.
STATE OF RUMOR: False
Donkey Kong
People had rumored that Donkey Kong appeared in Five Nights at Wario's 2, this was proven false, however, Donkey Kong will make an appearance in Five Nights at Wario's 3.
STATE OF RUMOR: False