When Yosei dies, Nim Deathmantle triggers, causing you to pay ({4} magic symbol) to return Yosei from your graveyard to the battlefield, and attach Nim Deathmantle to it.
When Yosei enters the battlefield, it triggers, causing target opponent to skip their next untap step, and tapping five permanents that opponent controls.
Repeat for each remaining opponent, and during each of your turns.