I just invented a fancily-named trope thanks to you. I call it the "Character Resurrection Impurity Hypothesis", and it is as follows:
The reason you want a character to come back is because of their admirable traits and/or what they were willing to do for their goals, but without good reason, bringing them back would therefore trivialize their death, and this trivialization is even more apparent if their death was sacrificial.
I totally know where you're coming from, but Xion coming back would totally annihilate the entire point of 358/2 Days. I mean, Xemnas is my favorite Kingdom Hearts villain, but I'd like him better DEAD. Bringing him back in Dream Drop Distance essentially defeated the entire purpose of KH2. butheythatsjustmeiguess
I apologize, but this is so wrong. You are aware that Xion is in a way Sora, but with scattered memories in a made up body. In other words, you're making it look like Sora is dating himself. Sora likes Kairi.