Cast Acererak by paying {B}.
When Acererak enters, its first ability triggers.
Holding priority, activate Relic of Legends' second ability by tapping Acererak, adding {B}.
Resolve the Acererak trigger, returning it from the battlefield to your hand, and venturing into Lost Mine of Phandelver.
Repeat.

Infinite card draw

Infinite draw triggers

Near-infinite +1/+1 counters

Near-infinite creature ETB

Near-infinite creature LTB

Near-infinite Treasure tokens

Near-infinite colored mana

Near-infinite creature tokens

Near-infinite lifegain

Near-infinite lifegain triggers

Near-infinite lifeloss

Near-infinite storm count

Near-infinite ventures into the dungeon

Acererak the Archlich

Relic of Legends

The Kenriths' Royal Funeral

Cast Acererak by paying {B}.
Bontu's Monument triggers, causing you to gain life and each opponent to lose life.
When Acererak enters, its first ability and Carnival of Souls trigger.
Resolve the Carnival of Souls trigger, causing you to add {B} and lose 1 life.
Resolve the Acererak trigger, returning it from the battlefield to your hand, and venturing into Lost Mine of Phandelver.
Repeat.

Carnival of Souls

Bontu's Monument

Cast Ebondeath from your graveyard by paying {B}{B}.
Geralf's first ability triggers, creating a 2/2 Zombie Rogue creature token.
When the Zombie Rogue enters the battlefield, Geralf's second ability triggers,  putting a number of +1/+1 counters on the Zombie Rogue equal to the number of other Zombies that entered the battlefield under your control.
When Ebondeath enters the battlefield, Geralf's second ability triggers, putting a number of +1/+1 counters on Ebondeath equal to the number of other Zombies that entered the battlefield under your control.
Activate Umbral Collar Zealot twice by sacrificing the Zombie Rogue and Ebondeath.
When the Zombie Rogue and Ebondeath die, Pitiless Plunderer triggers twice, creating two Treasure tokens.
Resolve both Umbral Collar Zealot abilities.
Activate the Treasures by tapping and sacrificing them, adding {B}{B}.
Repeat.

Combos with "The Kenriths' Royal Funeral"