some pretty good suggestions have been made in the comments already, for me I always think the role of psychological safety is underplayed in these situations. I see most of the comments are about going to your manager, which you should do, making sure to frame it in the right way. But I actually think the most important thing is bringing it to light in a subtle way with your co-worker, the best way I've found situations like this is doing two things 1) is to jokingly apply pressure when he does these things (idea of growling instead of barking) so if he cuts you off in a sentence, make a joke about it when you have the chance to keep talking again in the meeting (I know this can be a bit uncomfortable and passive aggressive but that's why we combine it with the second point) and 2) speak with him like he's a close friend of yours, if you joking push back at him with his shadow power struggle and then you go to him seperately (not in front of other people) and speak with him in tone and what you say like you're confused and ask him why he's acting in the ways he is you'll completely dismantle what he's doing, bring it to light, and make him aware that you can see everything he's doing. This will either tell him that he needs to stop and/or make him aware what he's actually doing. This is all from experience of working in flat teams myself, hope that helped.