MZD is the god of the Pop'n World, god of Lapistoria, and a DJ aside from all that. Acts carefree, but he takes his business seriously, so there's hopefully not much to worry about. Unless he forgets... also, he's accompanied by a living shadow that fans call Hatena.
In this game, he wields the white heart lapis.
L-an!ma by "Master of Lapis" (PON, wac and TAG) is his song.
So first and foremost, he created Lapistoria and Lapis Origin to watch over it while he was off doing god things(?). He didn't visit very much, leading to Origin feeling neglected...
At the start of the game, MZD calls upon Tsugidoka to investigate why Pop-kuns have gone missing in the Pop'n World, asking them to go to Lapistoria. He provides them with their lapises and tells them how to get there; after that, he's (mostly) absent until the climax of the story.
During the climax, he asks for Io and Lower to retrieve his lapis from Jade (who kept it after he and Orgin obtained it through unknown means), and for Mimi and Nyami to accompany him. He shows up properly right when all seems lost, becoming the catalyst for Origin's intentions to be revealed and for weakening it with the power of thought. He also enlightens a way to get back to the Pop'n World after it deactivates itself and, in the good ending, manages to revive it and return everyone's lapises!
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ATTACK/OPTIONS: "Hey, hey!" (オラオラ!)
DAMAGE: "You'll regret that!" (後悔するぜ)
GOOD PLAY: "Nice~" (よゆ~)
BAD PLAY: "Damn...!" (やべっ)
WIN: "It's 'cause I'm God~" (神だから~)
LOSE: "Good grief..." (やれやれ)
MZD without his glasses is cursed, but there's a bit of charm to it as well... Also, did you know that Christmas is real in the Pop'n Universe, including Lapistoria? Dude might have a son out there??? Who Is Pop'n Jesus?!??!?!?!!?!
I think the most qualified Pop'n Jesus is Navi from Usaneko. Do not ask me to elaborate.