HeartSeekers: A Helluva Boss/Kingdom Hearts AU.

After their respective worlds are consumed by a mysterious dark vortex, an axolotl demon named Xander and the assassin team from I.M.P. find themselves stranded in Traverse Town, a sanctuary for those whose homes have been destroyed. There, they are taken in by a group of enigmatic ninjas, Kakashi, Sasuke, Sakura, and Tsunade, who reveal that Xander is a chosen Keyblade wielder capable of battling the shadow creatures known as Heartless that are devouring the universe. Despite their trauma and initial reluctance, the members of I.M.P. agree to mentor Xander and join the fight against the darkness, driven by the slim, desperate hope that defeating the source of this universal threat will restore their fallen world and allow them to return home.