Even after he used his own body to seal the cursed Mother Elf, X visited the site where Zero was sealed. Part of it was out of frustration that Zero chose that course and part of it was simply out of missing the person he'd held dearest above all (which is the case whether or not they're paired, frankly).
X never gave up hope. For all the heartache of decades upon decades of conflict and how much it went against his very being, X held onto it.
His feelings on Copy are complicated. He doesn't approve of the reasons for his creation (I headcanon X thought of various contingency plans/guidelines in the event of his demise, etc.), and he doesn't approve of the lack of testing. Additionally, he's kind of appalled that anyone would try to recreate another individual. A life is not meant to replace another, but to be lived on its own in its own way. He understands why Copy turned out the way he did and how his thought process went the way it did on an intellectual and analytical level, but that doesn't make it okay. Had Copy been in a position, mentally, to be re-educated and guided? X might have said to take it. But unfortunately... This is where it gets complicated. Copy was, in short, too far gone. And X was livid. He thinks about it, sometimes, and isn't sure if he what he felt was right, but... He had front row seats to watching it all go down.
Depending, X might have tried reaching out to and communicating with Copy X (I can't really see X just letting all that go).
I joke about him being tiny and the games angle for 14 or so as his age, but I tend to portray X as being closer to 16 or a bit older (in any case, he appears only a little younger than Zero). Obviously this doesn't reflect mental maturity, and his AI has matured to the point of adulthood. And while canon I think suggests his height to be 5'3", I pin X at 5'5" due to an artbook thing I might've misread. But it's been a while and I'm not really all that inclined to change it.
Part of the reason for his personality shift is the slow descent into being so bloody tired that continuing to function when utterly, utterly alone was simply draining. But he couldn't die because he wasn't dead, yet, and he wanted to be there when Zero woke. After the destruction of his body, he refused to fade away because Zero still had work to do, and X didn't want him to face it alone. ...Some of this is canon with headcanon feels.
X views Harpuia, Fefnir, and Leviathan as his children, had a hand in their creation, and he had to suppress the urge to dote on them as such when they were first activated. He managed only because there was so much going on at the time.
X IS NOT GOOD AT AFFECTION beyond platonic or familial. He's really bad at it--or he's just really awkward about it. He will outright refuse it if not completely alone, from either ducking away or pushing or darting off a bit to get away. Just. Nope. He's easily flustered by that sort of thing. He's kind of a prude. ...Outside, anyway. He relaxes considerably about it when not potentially in sight of others.
He does not actually have his full armour on under that robe. Just the blast suit thing, boots, and gloves. I'm undecided on the style of his gloves, but...
I will think of more things, later.
