2When Phantom Steed enters the battlefield, its first ability triggers, exiling Abdel Adrian until Phantom Steed leaves the battlefield.
3Abdel Adrian leaves the battlefield, ending its effect, causing Wormfang Drake to return from exile to the battlefield.
4When Wormfang Drake enters the battlefield, its first ability triggers, exiling Phantom Steed.
5Phantom Steed leaves the battlefield, ending its effect, causing Abdel Adrian to return from exile to the battlefield.
6When Abdel Adrian enters the battlefield, it triggers, exiling Wormfang Drake and any number of other nonland permanents you control until Abdel Adrian leaves the battlefield and creating at least one 1/1 Soldier creature token.
7When Wormfang Drake leaves the battlefield, its second ability triggers, returning Phantom Steed to the battlefield from exile.