Thank you, Mary, for that analysis, so appreciated. It seems the more I know about a situation with my birds, the more it's plain I am helpless to really help.

His movements are definitely exaggerated-I'm glad that showed on the video, which is one reason I taped so long, to give a good picture of what's happening with him. I'm no expert, of course, but I thought of stroke, tumor and even parasites, though I have looked them all over frequently and have found no visible mites or anything like that. I can dose them with pour on Invermectin today, just in case, but that is probably the least likely scenario with him.
Unfortunately, separating him out is hard. There are only three hens in there. I'd have to take one for him and leave Aubrey with two. He does take awhile to fly up to the roost; he roams back and forth looking up there before he finally flies up; seems to almost be dizzy when he looks up. Tom put a board behind the 3" wide roost so they have an actual platform once he gets up there. I'd put him up there myself every night, but he freaks out if I reach for him and ends up running and in a heap on the floor with his head tucked under his chest. Once he even did a somersault over his head when I was trying to catch him. Stressing brings on a "spell". That is one reason I hate having roosters I can't handle as easily as I can Bash and Atlas. Even Hector doesn't freak out
that badly when I pick him up. He just struggles a lot, but I can at least calm Hector down. If Spike cannot eat or drink, of course, we'll have to euthanize him as we did with poor little Carly. I haven't seen an actual seizure with Spike like happened with Carly repeatedly, but if he ceases to be able to get sustenance, definitely time to act. He sure is trying still. And you saw him crow at the end if you watched that far. Goofy little man.
Mary, I am going to pass on these few tidbits on my channel, if you don't mind, just some information for other chicken owners to put in their knowledge arsenal. So many things are not in books (like most everything that happens to me, argh) on chicken keeping. Experience and knowledge combine to at least give comfort to others who see this sometimes alarming stuff.