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 Mysterious Limousine to return from exile to the battlefield.
When Mysterious Limousine enters the battlefield, it triggers, exiling Lumbering Battlement until Mysterious Limousine leaves the battlefield.
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 Mysterious Limousine 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.
Mysterious Limousine leaves the battlefield, ending its effect, causing Lumbering Battlement to return to the battlefield from exile.
Repeat from step 2.
This brilliant loop creates an endless cycle of exile and return by bouncing our key permanents off one another. When you cast Lumbering Battlement, its entry triggers the exiling of Abdel Adrian, Gorion's Ward, which in turn drops Mysterious Limousine back onto the battlefield to whisk Lumbering Battlement away again. That departure releases Abdel Adrian right back into play to restart the chain, feeding you endless enters-the-battlefield triggers, leaves-the-battlefield triggers, and an army of 1/1 Soldier tokens.