Sugar tends to think in "i" statements as if he's talking to someone else (and frequently imagines himself speaking to imaginary interviewers) but due to redirections and recorrections he tends to mostly think in images and feelings and not words at all.

Dylan uses "you" and "i" depending on whether or not he's talking to his imagined "ideal" self and his current "lesser" self. This is pretty consistent.

Kestrel uses "you" exclusively and tends to refer to herself as if she was talking about a different person entirely, but lacks the "i" Dylan usually has. her internal thought process is through the view of someone who is "watching" her.