self appointed leader, n.Definitions

A Self-appointed leader (n.) turns ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠up once a movement is big, announces "I'm your leader," exploits it for power, and leaves when the game ends.