Nath of the Gilt-Leaf makes an elf warrior at the begining of your upkeep by making an opponent discard a card.
In main phase sacrifice the elf warrior making an opponent discard 2 cards, making two more elf warriors.
Repeat this step until all opponent have no cards in hand.

Opponents can only have cards in hand when it isn't your turn

Lock

Nath of the Gilt-Leaf

Sadistic Hypnotist

Activate Sadistic Hypnotist by sacrificing Gray Merchant, causing target player to discard two cards.
Activate Chainer by paying nine life, returning Gray Merchant from your graveyard to the battlefield as a Nightmare in addition to its other creature types.
Gray Merchant enters the battlefield, causing each opponent to lose life equal to your devotion to black and causing you to gain life equal to the amount of life lost this way.
Repeat.

Infinite death triggers

Infinite creature ETB

Infinite lifegain

Infinite lifegain triggers

Infinite lifeloss

Infinite creature LTB

Infinite creature sacrifice triggers

Return all creature cards from all graveyards to the battlefield under your control

Chainer, Dementia Master

K'rrik, Son of Yawgmoth

Gray Merchant of Asphodel

Activate Sadistic Hypnotist by sacrificing a creature, causing you to discard Basking Rootwalla and Blazing Rootwalla into exile.
Basking Rootwalla and Blazing Rootwalla's madness abilities trigger.
Resolve the Basking Rootwalla trigger, causing you to pay {0} to cast it from exile.
When Basking Rootwalla enters the battlefield, Cloudstone Curio and Molten Echoes trigger.
Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand.
Resolve the Molten Echoes trigger, creating a token copy of Basking Rootwalla with haste.
When the creature token enters the battlefield, Cloudstone Curio triggers, returning Basking Rootwalla from the battlefield to your hand.
Resolve the Blazing Rootwalla trigger from step 2, causing you to pay {0} to cast it from exile.
Repeat steps 4 through 7 one additional time using Blazing Rootwalla instead.
Repeat from step 1.

Combos with "Sadistic Hypnotist"