When Lumbering Battlement enters the battlefield, it triggers, exiling Abdel Adrian until Lumbering Battlement leaves the battlefield.
Abdel Adrian leaves the battlefield, ending its effect, causing Journey to Nowhere to return from exile to the battlefield.
When Journey to Nowhere enters the battlefield, its first ability triggers, exiling Lumbering Battlement.
Lumbering Battlement leaves the battlefield, ending its effect, causing Abdel Adrian to return from exile to the battlefield.
When Abdel Adrian enters the battlefield, it triggers, exiling Journey to Nowhere 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.
When Journey to Nowhere leaves the battlefield, its second ability triggers, returning Lumbering Battlement to the battlefield from exile.
Repeat from step 2.
This infinite loop dances back and forth between exiling and returning your board to generate boundless value. By utilizing Lumbering Battlement's entry trigger to consume Abdel Adrian, Gorion's Ward, you trigger a cascade where Journey to Nowhere gets involved to continuously cycle both creatures in and out of exile. Because Abdel Adrian's entry effect lets you swallow up other nonland permanents alongside Journey to Nowhere, you aren't just looping the two main threats—you're also generating infinite creature tokens and infinitely blinking any extra permanents you care to bring along for the ride.