Cast Ephemerate by paying , blinking Fiend Hunter.
When Fiend Hunter enters the battlefield, its first ability and Preston trigger.
Resolve the Fiend Hunter trigger, exiling Abdel Adrian.
Resolve the Preston trigger, creating a copy of Fiend Hunter that is a 0/1 Illusion.
When the token Fiend Hunter enters the battlefield, its first ability triggers, exiling the nontoken Fiend Hunter until the token Fiend Hunter leaves the battlefield.
When the nontoken Fiend Hunter leaves the battlefield, its second ability triggers, returning Abdel Adrian from exile to the battlefield.
When Abdel Adrian enters the battlefield, it and Preston trigger.
Resolve the Preston trigger, creating a token copy of Abdel Adrian that is a 0/1 Illusion.
Put the token Abdel Adrian into your graveyard due to the legend rule.
The token Abdel Adrian's enters-the-battlefield ability triggers, choose not to exile a permanent.
Resolve the Abdel Adrian trigger, exiling the token Fiend Hunter and creating a 1/1 Soldier creature token.
When the token Fiend Hunter leaves the battlefield, it triggers, returning the nontoken Fiend Hunter from exile to the battlefield.
Repeat from step 2.
This loop relies on a clever chain of triggers to endlessly cycle your creatures in and out of exile. It all kicks off when you cast Ephemerate to blink Fiend Hunter, which invites Preston, the Vanisher to duplicate the creature into a fragile 0/1 Illusion. That illusion then exiles the original Fiend Hunter, which in turn frees Abdel Adrian from exile to trigger his own enter-the-battlefield ability. Abdel Adrian sweeps up the token Fiend Hunter, releasing the original Fiend Hunter right back to the battlefield so the entire process can begin anew. Along the way, Preston helps fuel your token generation and gives you an outlet to dismantle the opponent's board by sacrificing your endless parade of Illusions.