Mkay so I get that we all really want a killjoy movie but consider this too, a killjoy video game. You get to create your own killjoy, join the Fab Four or make your own group, fight against the BLI/nd, complete mini side quests that also add even more to the lore and idk just be a killjoy.
When I die, if my friends dont vandalize my grave than what kind of friends did I have. And my grave better say 'She joined the Black Parade, but remember, Killjoys never die.'