Bebop:
because fossor lived a very isolated last few years of his life, he has some fear of technology, and seeing that bebop has a gigantic death ray, he'd be a bit concerned and ask about his creator, assuming it's some wicked war criminal like fairfax, only that apparently she's just an old lady, in which case he responds apologetically
Drifter:
something something fossor not being aware of drifter being a literal murder hobo so he ends up being oddly nice to him without knowing he straight up skins people or something. drifter being drifter he doesn't tell him at all because he probably finds it amusing
Dynamo:
i think he would be okay with dynamo, but unlike him who still wants his body back, fossor has completely accepted that this will be his fate for the rest of time, which may give the professor some 'enlightenment' (badum tss)
i was thinking he could probably have an interaction with him wherein dynamo confides in his presence for 'not having a body of his own', wherein fossor replies that his body is 'right there with him', leaving dynamo in a bit of an awkward position lol
Grey Talon:
i think it was already obvious from the interaction, but fossor respects his elders a lot, so although he might come off like he's patronizing GT, he genuinely wants to be able to give him a peaceful passing, although GT probably just tells him to lock tf in
Kelvin:
from the small bits i've read, kelvin is supposed to be a revenant or wight trying to find out what happened to him due to his amnesia. i think fossor would applaud his determination but try to tell him that it might be for the best he doesn't find out, considering he himself died with a lot of regrets
Lash:
funny but i think he likes lash's confidence in himself and wishes he had the same. i think he has some sort of heightened empathy to realize his facade, but never calls it out directly and tries to just keep him from doing something stupid. like a distantly supportive father figure
McGinnis:
hate HATEE HATE HATE HATE HATE
Pocket:
pocket's assassination was the entire reason fossor stood up and finally said something about fairfax, so them being alive means a lot to him. he would try to ask about them and their views on their father to try to give the poor kid some comfort but i don't think pocket likes talking about it
Seven:
genuine horror, in contrast to kelvin, his determination is directed towards his own apotheosis. he only hopes he doesn't kill everyone in NYC, but he does mention he's indifferent to killing
Viscous:
what the ....cube