Nice return to Kingdom Hearts! About Marluxia, admittedly, it comes belated, like so much lore from this series, but the reasons for his attempted usurpation of the Organization comes from both 358/2 Days and Dream Drop Distance. Between the two revelations, the former unfortunately a case of a pet peeve of yours: hidden in menu dossiers, though in the form of the journal entries each member writes. Since that's never shown in the 1.5 cutscene movie version, I can tell you what it is, if you're interested. The Dream Drop Distance's revelation is part of the most major spoilers of that game, so I'll hold off on that one. I can say that it's rather well-intentioned for the Organization's cause on Marluxia's part. Unfortunate that it's not on the wiki, but that's probably because the Days half of the reasoning is so hidden.
Edit: Forgot your mention of DDD at the end, so you are aware of that revelation. That puts Marluxia's rebellion into context then
Oh the creation of the devil, Kingdom Hearts Chains of Memories. I utterly hate the card battle system in an ACTION RPG GAME, they don't work that way!My friend who is going to play KH HD Re 1.5 and 2.5 Remix, I advice him to skip Re Chains of Memories because of how utterly bullshit the battle system is in that game. He played them for awhile, and he said that he has no problems with the system and says Birth by Sleep is the complex one.I then answered that I love Birth by Sleep combat system and I have no problem with it, and I also said, tell me how do you think after you fought Vexen, then you know why.Also another good sleight that I found in a Lets Play, is Lethal Frame, which utterly destroys bosses. The skill pretty much pull a Clock On from Kabuto when using it.