Here is how the game works. Each person will embed a picture from Side 7 into a reply. The picture posted by the person who replies after them must either share a fictional character (edit: expanded to allow sharing a fictional universe instead of just the same fictional character) as the picture above it (with the character doing anything they wish, but they must be doing something), or be of other fictional characters doing the same activities (also counting as this is the two characters saying the same or similar dialogue).

I'll go first.

this seems like a fun game / cool idea but I feel like it's a little limiting! c: real quick though here's my find:

what if instead of requiring the exact same fictional character, the art could be of the same "type" of fictional character? maybe based on setting or theme, that way people aren't barred from linking pictures of OCs? :] 

so like in theory, the og suggestion for the "uno" approximation to be:
"same color" becomes "same character" or
"same number" becomes "same character activity"

my tweaked suggestion might be:
"same color" becomes "same type of character" (medieval, cyberpunk, historical, etc?)
"same number" remains "same character activity"

just a suggestion though! feel free to be like "nah" if it doesn't seem like a good direction

You mean like this, with an OC doing the same pose as Link above without anyone knowing what her fictional setting is?

Because people can change the fictional circumstances of OC's, they are the game's wild cards. They can be used to respond to any fictional setting and any fictional setting can be used to respond to them, though if a response to them is based on fictional setting, it must be the same fictional setting as the one they're responding to if they're used to respond to someone based on a fictional setting (I edited the OP to clarify fictional universes rather than just the characters).

Someone could, for example, respond to this with a picture of a fictional character posing like this character, or they can respond to it with another Zelda picture.

Also, if two fictional universes have crossed over in the past, even if non-canonical, they can be treated as the same fictional universe, as long as the crossover is a two-way crossover (so for example you can respond to a Ben 10 picture with a Generator Rex picture and vice versa).