>>29262585I'm willing to bet on Water/Ghost, since it is an anchor and a number of inanimate objects get possessed by ghosts. Steel/Ghost feels like a secondary idea, also because it's an anchor. I don't really see it being Grass at all just because there's some algae on it, but it's possible.
It could be Water/Steel as well, I just don't think that's too likely. Klefki isn't a ghost though, so who the fuck knows really.