mastermind

mastermind verb [ T ] uk/ˈmɑːstəmaɪnd/ us
to plan every detail of a complicated event or activity and make sure that it happens

разрабатывать и осуществлять (хитроумный план)
He allegedly mastermind ed both bomb attacks in the region. mastermind noun [ C ]

руководитель, вдохновитель
It is thought he was the mastermind behind (= the person who planned) last year's bombing campaign.