There's absolutly no way for the Dragon to win this.
He only has 3 options, wich can't even be applicable until he fully wakes up, so Zeno as more then enough time to erase him completly before the Dragon can even realize he's fighting. His methods of attack aren't even applicable by itself, since everything surrounding his powers depends on the heart of who wakes him up. If it is a good heart, he will reset the multi-verse to be a happy place, wich as best can make Zeno not want to fight, the second is if the one who wakes him up is a bad person, then everything that the user wants gone will be destroyed so satisfied it, but again, that depends in if there's a user in the first place, the Dragon as time to even wake up, and the user wants to delete Zeno. And the last option is the only one that can kill Zeno 100%, since if the person who wakes him up has no heart, then he will erase everything, even himself, so at best it can be a stalemate for him, but thats it. There's no way he can even fight without waking up before, this is a stomp.