i'm so torn between c!ranboo resembling mono or resembling six ...
because he resembles certain aspects of each in a sense.

six, in that she let go of mono with the intent of stopping the loop. attempting to fix things that seemed already so far gone only to ultimately cause the problem, letting mono go, and him becoming the tall man as a result. the exact thing she thought she was preventing.
c!ranboo picks people as opposed to sides with the intent of not hurting others, and with the countless people who he's inevitably crossed in doing so, he's only done the same as six. tried to do something for the sake of others only to ultimately hurt them in the end.
NOW! for how i think he ties into being similar to mono. when he ends up stuck in the loop, stuck in the tower, he becomes corrupted and weak. he grows into the tall man, the last thing we all know he would've wanted for himself. he became the exact thing he feared most.
who does that sound ressemblent of, hm? c!ranboo. slowly but surely, c!ranboo is rapidly going downhill mentally and likely falling further in dream's grasp without even realizing he is, given the "i won" spelled out in ranboo's inventory in the last dsmp stream.
a lot of c!ranboo's habits are heavily ressemblent of earlier c!dream, when he still had hope. but it's not going to last. we're watching c!ranboo become the very thing he's trying to fight against.
those who do not learn from history are doomed to repeat it.
the entire theme of little nightmares is that things can't be fixed, that the loop is inevitable. in trying to prevent the loop, you're only ultimately progressing the loop instead and only perpetuating the underlying problems, to never be let free no matter how hard you try.