Ahhh yeah, that's what I meant by 'better grip in his mind', since back then he didn't seem completely lucid (makes me curious about the ~2 year gap between his fight with Shiro). The RAWs I've got have the chapters after 21 use boku IIRC (haven't checked the end of chapter 21 for a swap though). The "I" swapping isn't something that I've figured out how to represent in English, but it's nice to know regardless.