You have any number of other nonland permanents that enter the battlefield untapped, and that can collectively tap to produce enough mana to cast Ghostly Flicker exiled by Abdel Adrian.
Timeless Witness exiled by Abdel Adrian.
You have enough mana to cast Ghostly Flicker.
Steps
1Cast Ghostly Flicker by paying its mana cost, blinking Abdel Adrian.
2Abdel Adrian leaves the battlefield, returning Timeless Witness and all other cards that were exiled with it to the battlefield.
3Abdel Adrian and Timeless Witness trigger.
4Resolve the Timeless Witness trigger, returning Ghostly Flicker from your graveyard to your hand.
5Holding priority, activate any number of nonland permanents you control by tapping them, adding at least enough mana to cast Ghostly Flicker.
6Resolve the Abdel Adrian trigger, exiling Timeless Witness and the mana-producing permanents until Abdel Adrian leaves the battlefield, and creating a 1/1 Soldier creature token for each permanent exiled this way.