How to defeat Vanitas of Kingdom Hearts 3
Jumping Strike Down
Vanitas jumps down from the sky, smashing the ground with his keyblade. Ice is generated from the ground he strikes.
Shadow Dive and Fire Spin
Vanitas dives down into a shadowy circle which rushes towards Aqua. While inside the circle, he cannot be hit with physical attacks.
Once he gets in range, he springs up a shadowy circle and spews fireballs all over the map. This deals quite a lot of damage, so it is best to steer clear when he rises from the shadowy circle.
Vanitas shoots two fireballs in succession. Their speed is somewhat slow which makes them easy to dodge. However, multiple fireballs can be a bit hard to dodge, so it is best to keep distance. This allows you to see how many fireballs he tosses out.
Taking down Vanitas
Use Magic Attacks
Vanitas has a fast attack speed which makes the openings between his strikes short. Therefore, try to magically attack from as far back as possible with Aqua. Make it a point to use your magic attacks just as he lunges for an attack in order to stagger him.
Using Spell Weaver
While recharging MP with a magic attack, use the situation command “Spell Weaver.” A whirlwind of ice envelopes Aqua and she can spin towards Vanitas to deal a good amount of damage.