[quote=@Mr Allen J]

[indent][b]Would the Multiverse already made contact or no?[/b]
[indent]This might just be me reading into things, but this could prove interesting if we want to avoid the same cliches that are abundant in multiverse RPs, [i]and[/i] have pre-existing relationships.[/indent]

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[/quote]

Perhaps?

There's a fair amount of crossovers and references between a lot of these shows that could provide existing relationships in one way or another by default. (KND and Grim Adventures being one of the older ones I can think of; Specifically the one where Grim loses his powers and Numbuh 3 takes his job for a 1 month trial period.)

[url=http://cnmultiverse.wikia.com/wiki/Crossover_Episodes]This list[/url] Coverssome of the Cartoon Network crossover episodes over the years. Could be a good place to start.