What if Fushimi was a vessel to Munakata like Totsuka was to Mikoto?? How would Homra and s4 react??
By ‘vessel’ I’m assuming you mean he’s kinda working as Munakata’s stopper the way Totsuka was to Mikoto? Actually this would be an interesting development after S1, like previously Munakata was entirely in control of his own Weismann level and had no need for a Totsuka but now after the death of Mikoto he’s more unstable and Fushimi of all people seems to help him keep his powers in check. I can see Fushimi taking this in a totally bad way though, like obviously Munakata suffered some mental distress after being forced to kill Mikoto (even if the series decided to like never really dwell on it at all) and Fushimi helps him keep himself stable. For Munakata maybe this is simply a question of stability, like he considers Fushimi to be somewhat like himself in many ways, someone who has a keen intellect and is different from other people and that helps keep him rooted. But for Fushimi I’m sure he’d take this as just like another way in which he is inferior to Mikoto in the mind of someone he cares about, like Fushimi assumes the reason he’s become Munakata’s stopper is because he has Red powers and it’s that link to Mikoto that’s keeping Munakata’s levels from dropping to even more dangerous levels (oh or what if that was actually partially it though, like keeping close someone who still contains that bit of the man Munakata killed in his soul helps stabilize Munakata’s Weismann level and it has nothing to do with Munakata’s feelings or decisions, it’s just a quirk of the Slate).
I think Fushimi being in that position would be both surprising and concerning for everyone. Like I can see Kusanagi and Awashima discussing it, Awashima’s glad that Captain has someone to stabilize him (even if maybe part of her feels as if she’s failed him somehow that she couldn’t be this for him) but they both know that Fushimi himself is not the most stable person ever and there’s concern as to what could happen if Fushimi’s own mental state cracks. This also makes Fushimi more of a target and Yata would probably worry a lot about that, wondering how the hell Saruhiko ended up being so close to the Blue King and won’t people come after him now as a way of getting to Munakata. I think there would also be worry just in general because of how things turned out with Mikoto, like the danger of having one person who’s keeping the King stable is clear and is this just going to lead to a repeat of what happened in S1 if they can’t keep Fushimi safe (also imagine how this changes what happens in ROK with the fake betrayal, Munakata sending Fushimi away even though he knows this will destabilize him and may lead to both their deaths but he does it anyway because he believes that it’s the only path to victory).