1. Move all the way up to the edge of the screen.
2. Stand close enough so the dragon straightens his neck, if he lifts his head then you are too close and he can burn you or eat you. Once you have found this sweet spot keep it in mind.
3. When his neck is straight and you are right in front of him he will breathe in to shoot at you horizontally. When he is about to do that, move downward, your moving speed will be faster than the dragon downward speed as he tries to catch up to you while breathing fire. When there is enough safe distance and he is still breathing fire, reach for the bottom side of his head so your hits can make collision.
4. If you get really close like in line to where the eye is or even further (while he is still shooting). Do an upper slash, just hold up+Fire, you will do only 1 frame of animation and hit, on loop and hit him like 4-10 times (you basically stunlock him into the wounded animation).
This in my opinion is an exploit which makes this fight the easiest in game.
Post edited January 23, 2021 by Artcakes