Comment by 29athrowaway

He is using meetings as a dominance/humiliation ritual, and disagreement as an insult delivery mechanism. He is in disagreement with the hierarchy, uses disagreement to show defiance because he wants to be the leader. He also perceives he does not have much to lose by doing this because in the worst case scenario he will just go be an individual contributor elsewhere, and in the best case scenario you would leave, your role would be vacant and he may be eligible for it again.

The first thing you will do, is to talk to individual people by name. Do not ask open questions that everyone can respond to, because he will use that opportunity to be toxic. If he does intervene in a toxic way, you will continue addressing the person you were talking to, by name, and not pursue his talking point. This is fair game because you were not talking to him.

Secondly, instead of having long meetings with the entire team about every topic, you will have a general high level meeting with the team, and dedicated meetings for navigating the actual solutions with specific team members. You will not discuss solutions at length in the front of the entire team, and if you do, see the point above. You will also try to have clear agendas and expectations for meetings.

Thirdly, if he wants to initiate a conversation, try to scope it to what he was working on. Until you mobilize him to work on something else or ask for his opinion, other initiatives are not his primary concern. You can ask "tell me how the initiative X is going", or "what are your current priorities at the moment" to frame the conversation, and steer the conversation so that it stays on topic. If he refuses to answer just say "he will revisit your priorities later" and talk to someone else.

Lastly, if he operates outside the direction given by you as a lead, or consensus of the team, document it. And if it has consequences, document them. Create a clear paper trail that shows that he is not an individual contributor that can be mobilized towards a goal and is a liability for the organization.

Until he fixes his attitude, never ask for his advice in terms of "what would you in this situation if you were me", but you may ask others this.