KH Re: Chain of Memories (1.5 + 2.5 ReMIX) - Vexen boss fight
91[WARNING: THIS VIDEO FEATURES SPOILERS FROM THE MAIN STORY OF KINGDOM HEARTS RE: CHAIN OF MEMORIES]
This video features the boss fight against Vexen from Kingdom Hearts Re: Chain of Memories (the PS2 remake of the original GBA game). Truth be told, this fight occurs at the end of Twilight Town after a brief one you have with Vexen in the hallways of Castle Oblivion right before entering the Town proper. Said fight is however very brief and much easier and can be considered just a preview of the second one, where Vexen will use his abilities to the fullest.
Note that this video was recorded while playing Kingdom Hearts Re: Chain of Memories on its 1.5 ReMIX version from the 1.5 + 2.5 ReMIX compilation for the Playstation 4 and on Standard difficulty. I was also playing on my Playstation 4 Pro.
Vexen manages to be one of the most challenging bosses on the Sora's side of the game due to his incredible resilience. Not only his shield means that the only way to attack him effectively is to break his cards or strike him from behind, but the boss packs a lot of item cards to recover his magic and attack cards quickly (and can use the Air Pirate card to make said cards unbreakable for a short while) and his own enemy card involves Vexen being "resurrected" after being defeated a first time and recovering a nice chunk of HPs, further prolonging the fight. Also, Vexen attack cards values are usually pretty high.
The more "careful" way to defeat Vexen is to play defensively and break his cards sistematically in order to catch the boss off-guard and land some hits. Also, as it's shown in the video itself, there are certain sleights that can bypass Vexen shield and dish out a lot of damage to him (moreso fire-based sleights, since it's the element Vexen is weak against)