The Final Battle in Paper Mario: Color Splash
In the first phase you have to free Bowser’s head from the black paint. Make sure that you do not attack Bowser with normal jump attacks due to the horns. You should also destroy the black lava bubbles, because at the end of the round it absorbs Bowser and gets black paint back.
In the second phase, you must not only free Bowser from the paint with attacks, but also lock the black paint with a successful defense in Huey. However, the following attacks by Bowser also do a lot of damage despite successful defense, so make sure that your HP is sufficiently filled. Especially critical is the last attack, if the defense fails, there is not only plenty of damage, but Bowser will also regenerate strongly. Do not press too hard on the defensive button, because the black ball flies towards you rather slower. If you fend off this attack, you can end the fight with a successful jump attack!