Activate Helvault by paying {1} and tapping it, exiling Kami of Industry.
Activate Krark-Clan Ironworks by sacrificing Helvault, adding {C}{C}.
Helvault leaves the battlefield, returning Kami of Industry from exile to the battlefield.
Kami of Industry enters the battlefield, returning Helvault from your graveyard to the battlefield.
Repeat.

Infinite colorless mana

Infinite creature ETB

Infinite creature LTB

Kami of Industry

Helvault

Krark-Clan Ironworks

Activate Helvault by paying {1} and tapping it, exiling Sharuum.
Activate Krark-Clan Ironworks by sacrificing Helvault, adding {C}{C}.
Helvault triggers, returning Sharuum to the battlefield from exile.
Sharuum enters the battlefield, returning Helvault from your graveyard to the battlefield.
Repeat.

Sharuum the Hegemon

Activate Helvault by paying {1} and tapping it, exiling Scholar of the Lost Trove.
Activate Krark-Clan Ironworks by sacrificing Helvault, adding {C}{C}.
Helvault leaves the battlefield, returning Scholar of the Lost Trove from exile to the battlefield.
Scholar of the Lost Trove enters the battlefield, casting Helvault from your graveyard without paying its mana cost.
Repeat.

Combos with "Helvault"