honestly keith is in a super bad mental place right now yet i haven’t really seen that many people… care?
now i hate to say this, but if it was lance going through all of what keith’s going through right now? you know the fandom would be going CRAZY.
…but it’s not. it’s keith.
his teammates all keep dying around him left and right, he keeps nearly escaping death (like when he was stuck in space in e1), and he’s being given a bad mindset just being with the blade altogether. but that’s not even all of it.
we all know keith pushes people away before they reject him, but how do you think he felt when the team, the only family and friends he has, did reject him?
as someone super similar to keith, i can tell you that does not feel good at all.
and i know they ended it all with a hug saying they’ll always be there for him, but don’t tell me it didn’t hurt keith when not a single one of them actually said they wanted him to stay.
especially when shiro knows the blade of marmora way. victory/knowledge or death. and he knows how keith is.
(which shows this shiro… isn’t s2 shiro. that shiro would’ve stopped keith from staying with the blade, like how he tried stopping him from doing the trials.)
now there are really only two reasons keith stays with the blade in the first place.
now that shiro can pilot black again, keith doesn’t feel as if he has a place on the team (similarly to lance). now we do know part of the reason he’s been with the blade so much is because he didn’t like being the leader. he didn’t want that position. he was forced into it, then always criticized for being bad at it. now he did get somewhat better near the end with the help of lance, but i don’t think he realized it. (lance is the only one on the team who ever acknowledged him as leader besides shiro, after all.)
keith tried staying off the team since s3e6, after lance opened up to him. he tried to give black to shiro (which we all know didn’t work) and he let lance have red. so he truly feels he doesn’t belong on the team anymore. the team not stopping him from just straight up leaving cemented that.
the other reason keith stays with the blade is to get a sense of identity. he’s had his knife all his life, it’s his only real connection to who he is. but he’s learning the blade way, the galra way, and it’s not good for him. they keep telling him “the mission is more important than the individual”, which shows why so many bom members we’ve seen (thace, ulaz, etc) have sacrificed themself for the greater good.
keith tried sacrificing himself not only for the mission, but because he believed the team would benefit more having him dead than alive. he didn’t say goodbye to anyone before he did it, not even matt, who he was already talking to. he doesn’t think he matters. he’s just another casualty that (would’ve) died for the cause.
in conclusion keith’s mental state right now is bad. he’s not selfish for leaving the team. he did it because he doesn’t think they need him anymore. he doesn’t think he matters.
and it’s the blade that’s really cementing this in his mind.