Cast Abdel Adrian from the command zone by paying {4}{W} and command tax, if applicable.
When Abdel Adrian enters the battlefield, it triggers, exiling Hostage Taker and creating a 1/1 Soldier creature token.
When Hostage Taker leaves the battlefield, Felidar Guardian returns from exile to the battlefield.
When Felidar Guardian enters the battlefield, it triggers, blinking Abdel Adrian.
Abdel Adrian leaves and re-enters the battlefield, causing Hostage Taker to return from exile to the battlefield, and triggering both Hostage Taker and Abdel Adrian's abilities.
Resolve the Hostage Taker trigger, exiling Felidar Guardian until Hostage Taker leaves the battlefield.
Resolve the Abdel Adrian trigger, exiling Hostage Taker and creating a 1/1 Soldier creature token.
Repeat from step 3.

Infinite LTB

Infinite ETB

Infinite creature tokens

Infinite blinking of nonland permanents you control

Abdel Adrian, Gorion's Ward

Hostage Taker

Felidar Guardian

Activate Kiki-Jiki by tapping it, creating a token copy of Hostage Taker.
When the Hostage Taker token enters the battlefield, it triggers, exiling Kiki-Jiki until Hostage Taker leaves the battlefield.
Activate Ashnod's Altar by sacrificing the Hostage Taker token, adding {C}{C}.
When the Hostage Taker token dies, Kiki-Jiki is returned from exile to the battlefield.
Repeat.

Infinite sacrifice triggers

Infinite death triggers

Infinite colorless mana

Kiki-Jiki, Mirror Breaker

Ashnod's Altar

Cast Sister Hospitaller by paying {4}{W}{B}.
When Sister Hospitaller enters, it triggers, returning Hostage Taker from your graveyard to the battlefield and causing you to gain life equal to its mana value.
When Hostage Taker enters, it triggers, exiling Sister Hospitaller until Hostage Taker leaves the battlefield.
Activate Viscera Seer by sacrificing Hostage Taker.
When Hostage Taker leaves the battlefield, Sister Hospitaller is returned from exile to the battlefield.
Repeat from step 2.
Resolve all Viscera Seer abilities.

Infinite scry 1

Infinite lifegain triggers

Infinite lifegain

Sister Hospitaller

Viscera Seer

Cast Metamorphosis Fanatic by paying {4}{B}{B}.
When Metamorphosis Fanatic enters, it triggers, returning Hostage Taker from your graveyard to the battlefield.
When Hostage Taker enters, it triggers, exiling Metamorphosis Fanatic until Hostage Taker leaves the battlefield.
Activate Viscera Seer by sacrificing Hostage Taker.
When Hostage Taker leaves the battlefield, Metamorphosis Fanatic is returned from exile to the battlefield.
Repeat from step 2.
Resolve all Viscera Seer abilities.

Metamorphosis Fanatic

Cast Hostage Taker by paying {2}{U}{B}.
Hostage Taker enters the battlefield, exiling Angel of Glory's Rise.
Activate Altar of Dementia by sacrificing Hostage Taker.
Hostage Taker leaves the battlefield, returning Angel of Glory's Rise from exile to the battlefield.
Angel of Glory's Rise enters the battlefield, returning Hostage Taker from your graveyard to the battlefield.
Repeat from step 2.
Once you have a large amount of Altar of Dementia abilities on the stack, you may stop the loop and resolve them to cause target player(s) to mill infinite cards.

Infinite mill

Infinite self-mill

Angel of Glory's Rise

Altar of Dementia

Cast Hostage Taker by paying {2}{U}{B}.
Hostage Taker enters the battlefield, exiling Angel of Glory's Rise.
Activate Ashnod's Altar by sacrificing Hostage Taker, adding {C}{C}.
Hostage Taker leaves the battlefield, returning Angel of Glory's Rise from exile to the battlefield.
Angel of Glory's Rise enters the battlefield, returning Hostage Taker from your graveyard to the battlefield.
Repeat from step 2.

Cast Hostage Taker by paying {2}{U}{B}.
Hostage Taker enters the battlefield, exiling Angel of Glory's Rise.
Activate Phyrexian Altar by sacrificing Hostage Taker, adding one mana of any color.
Hostage Taker leaves the battlefield, returning Angel of Glory's Rise from exile to the battlefield.
Angel of Glory's Rise enters the battlefield, returning Hostage Taker from your graveyard to the battlefield.
Repeat from step 2.

Combos with "Hostage Taker"