Many- a-time, disruptive personalities thrive in dysfunctional work environments. The initial expectation would be that such a person will soon be set right. But this usually does not happen, for a variety of reasons, but mostly due to inertia and typical dysfunctional office dynamics.
Do not count on external forces to deal with a disruptive force in your project. The sooner you can call out the offender – the better. Keep your facts straight. The offender should realise that you are serious. Stick to the facts – do not allow the discussion to veer off on a tangent – mainly because this is what this person will attempt to do.
Be honest and call out the facts as you see them – in private, with the offender, followed by a detailed email capturing this in writing. About 90% of the time, you will fail in getting any behavioral changes effected, purely because of the psychological makeup of the offender. You will then be forced to escalate this with a superior, but at least you have the defence that you made a sincere attempt to address this with the person concerned.