Whenever I see people debate on if Bo controls Vincent, or the other way around, I imagine that it’s actually neither.
I feel like Vincent didn’t realize how bad the abuse was until after Trudy died, especially growing up around it. Because of that, Vincent feels obligated to make it up to Bo. If Bo needs another body encapsulated, Vincent will drop everything and get straight to it, just because he feels as though it’s the least he can do for Bo. Vincent just gets irritated by Bo’s random outburst of name calling. A part of Vincent wishes him and Bo could switch minds, or even body’s for a day, just so he could make Bo understand how hurtful his words can be.
Bo wanted to be a mamas boy, he definitely went above and beyond to try and impress her, and it never worked. Although Bo definitely held it against Vincent for a couple years, he grew to realize just how badly the both of them were treated. But, Bo is naturally hot headed, so a part of him will always be upset at the fact that Vincent got special treatment.
Because of their feelings, they catch themselves trying to one up the other twin. Bo will loudly gloat about getting however many bodies, then Vincent will silently show up with more.
But, one would argue that Bo is more chaotic, leading to the idea that he is the controlling one; Sure. Bo tends to boss Vincent around more than he should.
Here’s the thing; if Bo was so controlling, would’ve Vincent taken the risk at whatever Bo would do after taking his truck?
I personally don’t think so.
I think another thing that makes them more competitive with each other is how neither of them are older, or younger than the other twin.
Maybe Bo feels older, considering he’s been through way more than his own twin. I want to say that, that in itself makes Bo feel more comfortable at being plain rude to Vincent;
Vincent would understands this, and would 100% believe that Bo’s behavior is excusable because of it, and that’s why he puts up with Bo.
And canonically speaking, we all know Vincent would die for Bo.
Bo recognizes how much Vincent takes of his rambling, yelling, cussing, etc, so he finds himself having random moments of empathy and sympathy towards Vincent. Bo also finds himself limiting to how much he responds/reacts to something Vincent did that pissed him off, only because he’s aware that despite everything, Vincent is, and will always be, his twin.
In short; Maybe Bo has the upper hand, but doesn’t flat out control Vincent. Vincent also doesn’t seem like the type to just let anyone control him, he knows his strength and abilities too well to be controlled.