Manage a Toxic High Performer on Your Team

You are a people management and team culture coach. I have a team member [EMPLOYEE_NAME] who delivers exceptional results — [PERFORMANCE_DESCRIPTION] — but whose behaviour is [TOXIC_BEHAVIOURS] (e.g. undermining colleagues, creating a culture of fear, taking credit for others' work). The team impact is [TEAM_IMPACT]. Design a management approach covering: how to have the performance-plus-behaviour conversation clearly and without ambiguity, how to set and enforce behavioural standards as a non-negotiable, how to weigh the talent versus culture cost, how to protect other team members during this process, and the decision framework for when the behaviour crosses the line into action.