[ Register or Signin to view external links. ]
Data Vanitas is of the main bosses of Kingdom Hearts 3 Re:Mind Datascape Radiant Garden. The following Kingdom Hearts 3 ReMind Vanitas Boss guide will help you understand Data Vanitas' moveset and how to attack him.

Kingdom Hearts 3 ReMind Vanitas Boss
Before starting the boss fight, we would recommend you take Ultima Weapon and Kupo Coin with you. You can easily purchase the Kupo coin from a Moogle shop.

For abilities, we would recommend the following:

Glide
Block
Counter Impact
Counter Kick
Final Blow
Payback Strike

It is recommended to be at least level 80 before you head out to face Data Vanitas in the Limit Cut Episode.

Throughout the boss fight, Vanitas will use the following attacks. It is best to use Sora during this KH3 ReMind boss fight to make quick work of your enemies.

Slash Wave Attack: Data Vinatas will slash a wave that will freeze Sora if it connects. Even though this attack has range, it can be both dodges or blocked.
Shadow Dive: Data Vinatas will rise, phase out then teleport near Sora to attack. The attack can be blocked but it is better to dodge out of it.
Fire Balls: During Shadow Dive, Data Vanitas also has the ability to shoot Exploding Fire Balls around him. They have an area attack and can also heat up the ground. The attack can be blocked. Otherwise, he can hurdle Volleyballs of fire towards Sora, which can also be blocked.
Continous Slash: A bit different than a single slash wave, as Data Vanitas will send three slash back to back, the last of which can slow Sora.
KeyBlade Ride: Data Vinatas will jump on a tornado of keyblades and attempt to smash them to Sora.
Ice Missle: Data Vinatas will shoot Icicle Projectiles at Sora. These will freeze Sora, even if Blocked so dodge them.
Unversed Wave Attack: Data Vinatas will go to the center of the arena and summon Unversed monsters to fight you.

Fighting Tips

Approach Data Vanitas after he has completed his attacks. This ensures you get an open, safe window to deal damage without getting hit.
Block all ranged attacks from Data Vanitas, except the Ice missiles. Dodge them as they will freeze you whether or not you block them.
When Data Vinatas initiate his Keyblade Ride, there is a small window to hit him but is a risky move, so it's better to just avoid his attack.

Sora gets an AP boost that permanently raises maximum AP by 1 after defeating Vanitas in KH3 ReMind Limit Cut episode.