Intruder Alarm's first ability prevents creatures from untapping during their controller's untap step.
Because Hushbringer prevents abilities from triggering whenever a creature enters the battlefield, Intruder Alarm's second ability does not trigger to untap them.

Creatures do not untap

Lock

Intruder Alarm

Hushbringer

Blink Wormfang Manta using Soulherder. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Infinite turns

Wormfang Manta

Soulherder

Blink Wormfang Manta using Teleportation Circle. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Teleportation Circle

Blink Wormfang Manta using Y'shtola Rhul. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Y'shtola Rhul

Declare any creature as an attacker, attacking an opponent unable to block it.
When the creature is unblocked, activate Phage's ninjutsu ability by paying {2}{U}{B} and returning the unblocked creature to your hand, putting Phage onto the battlefield tapped and attacking.
Phage enters the battlefield, however its ability does not trigger due to Hushbringer.
Deal combat damage with Phage.
Phage triggers, causing the opponent to lose the game.

Target opponent loses the game

Satoru Umezawa

Phage the Untouchable

Activate Flickerform by paying {2}{W}{W}, exiling Wormfang Manta and all Auras attached to it.
When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one.
At the beginning of your end step, Flickerform triggers, returning Wormfang Manta from exile to the battlefield, and then returning all Auras that were attached to Wormfang Manta from exile to the battlefield attached to Wormfang Manta.
Wormfang Manta's first ability does not trigger due to Hushbringer.
Repeat each turn.

Flickerform

Activate Erratic Portal by paying {1} and tapping it, returning Wormfang Manta from the battlefield to your hand.
Wormfang Manta leaves the battlefield, triggering its first ability, causing you to take an extra turn after this one.
Cast Wormfang Manta by paying {5}{U}{U}.
Wormfang Manta enters the battlefield, but its first ability does not trigger due to Hushbringer.
Repeat each turn.

Erratic Portal

Blink Wormfang Manta using Don & Leo. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Don & Leo, Problem Solvers

Blink Wormfang Manta using Meneldor. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Meneldor, Swift Savior

During your precombat main phase, cast Wormfang Manta by paying {5}{U}{U}.
Wormfang Manta's first ability does not trigger due to Hushbringer.
Activate Wizard Mentor by tapping it, returning it and Wormfang Manta from the battlefield to your hand.
When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one.
Cast Wizard Mentor by paying {2}{U}.
Repeat each turn.

Wizard Mentor

Cast Mercurial Pretender for {4}{U}, entering as a copy of Wormfang Manta.
Pay {2}{U}{U} to return it to your hand, triggering Wormfang Manta's LTB, granting you an extra turn after this one.
Repeat for infinite turns.

Mercurial Pretender

At tbe beginning of your combat phase, Mirage Phalanx and Wormfang Manta trigger.
Resolve the Mirage Phalanx trigger, creating a token copy of it with haste and that doesn't have soulbond.
Resolve the Wormfang Manta trigger, creating a token copy of it with haste.
The Wormfang Manta token's first ability does not trigger due to Hushbringer.
At the end of your combat phase, the Mirage Phalanx and Wormfang Manta tokens trigger, exiling themselves.
The Wormfang Manta token's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Mirage Phalanx

Attack with Ilharg.
Ilharg's attack trigger triggers, putting Wormfang Manta onto the battlefield tapped and attacking.
At the beginning of your end step, Wormfang Manta is returned to your hand.
This triggers its LTB, granting you an extra turn after this one.
Repeat for infinite turns.

Ilharg, the Raze-Boar

Blink Wormfang Manta using The Mind Stone. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

The Mind Stone

Blink Wormfang Manta using Airbender Ascension. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

Airbender Ascension

During your precombat main phase, cast Wormfang Manta by paying {5}{U}{U}.
Wormfang Manta's first ability does not trigger due to Hushbringer.
Activate Lady Sun by tapping it, returning it and Wormfang Manta from the battlefield to your hand.
When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one.
Cast Lady Sun by paying {1}{U}{U}.
Repeat each turn.

Lady Sun

Cast Sakashima for {2}{U}{U}, entering as a copy of Wormfang Manta.
Pay {2}{U}{U} to return it to your hand, triggering Wormfang Manta's LTB, granting you an extra turn after this one.
Repeat for infinite turns.

Sakashima the Impostor

Blink Wormfang Manta using The Neutrinos. Wormfang Manta's first ability won't trigger due to Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Repeat each turn.

The Neutrinos

Activate Ashnod's Altar by sacrificing Wormfang Manta, adding {C}{C}.
Wormfang Manta dies, triggering its second ability, causing you to take an extra turn after this one.
Activate Conduit of Worlds by tapping it, allowing you to cast Wormfang Manta from your graveyard this turn.
Cast Wormfang Manta by paying {5}{U}{U}.
Wormfang Manta enters the batltefield, but its first ability does not trigger due to Hushbringer.
Repeat each turn.

You can't cast spells

Conduit of Worlds

Ashnod's Altar

Declare Sophina and two other nontoken creatures as attackers.
Sophina triggers, creating three Clue artifact tokens.
Activate Ashnod's Altar by sacrificing Wormfang Manta, adding {C}{C}.
Wormfang Manta leaves the battlefield, causing you to take an extra turn after this one.
If Wormfang Manta was put onto the battlefield by Havengul Mystery, Havengul Mystery triggers, transforming itself.
Activate the Clue tokens by paying {6}, tapping and sacrificing them, causing you to draw three cards.
At the beginning of your end step, Havengul Laboratory triggers, transforming itself.
Havengul Mystery triggers, returning Wormfang Manta from your graveyard to the battlefield.
Repeat each turn.

Combos with "Hushbringer"