Is there a particular reason why we're required to play as pre-existing characters from pre-existing media? Why I do find this idea intresting, the thought of having to play a character that belongs to an existing universe/series, and having to play that character in line with how they act, think and feel just doesn't appeal to me.

If this is a hard-set, must-be rule, I completely understand and in that cae, I'll be passing on this. But if there's not a heavy, decisive and incredibly plot-relevant reason for why this is the case, then perhaps we could negotiate?