Cast Culling the Weak by paying {B} and sacrificing Scholar of the Ages, adding {B}{B}{B}{B}.
Cast Shallow Grave by paying its mana cost, returning Scholar of the Ages from your graveyard to the battlefield.
When Scholar of the Ages enters, it triggers, returning Culling the Weak and Shallow Grave from your graveyard to your hand.
Repeat.

Infinite black mana

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite magecraft triggers

Infinite storm count

Return all instant and sorcery cards from your graveyard to your hand

Scholar of the Ages

Shallow Grave

Culling the Weak

Cast Burnt Offering by paying {B} and sacrificing Scholar of the Ages, adding seven mana in any combination of {B} and/or {R}.
Cast Shallow Grave by paying {1}{B}, returning Scholar of the Ages from your graveyard to the battlefield.
Scholar of the Ages triggers, returning Burnt Offering and Shallow Grave from your graveyard to your hand.
Repeat.

Infinite red mana

Burnt Offering

Cast Spellseeker, stacking Inalla's trigger under Spellseeker's ETB trigger.
Tutor Culling the Weak to hand with Spellseeker's ability.
Cast Culling the Weak, sacrificing Spellseeker and adding {B}{B}{B}{B}.
Resolve and pay for the Inalla trigger from earlier, creating a token copy of Spellseeker and leaving {B}{B}{B} floating.
When the token ETBs, tutor Unearth to your hand.
Unearth Spellseeker, leaving {B}{B} floating.
Shortcut resolving both Inalla's trigger and Spellseeker's ETB, tutoring for Burnt Offering and Finale of Promise, leaving {B} floating.
Cast Burnt Offering, sacrificing Spellseeker and adding {B}{R}{R}.
Use that mana to cast Finale of Promise with X=1 targeting Unearth and Culling the Weak.
Sacrifice a Spellseeker token to Culling the Weak for {B}{B}{B}{B} and Unearth Spellseeker.
Resolve Spellseeker's ETB and Inalla's trigger, tutoring Entomb and Reanimate into hand.
Entomb and then Reanimate Archaeomancer, leaving {B} floating.
Resolve Archaeomancer's ETB, returning Burnt Offering from your graveyard to your hand.
Cast Burnt Offering on Archaeomancer, adding {B}{B}{B}{B}.
Resolve the Inalla trigger from when Archaeomancer ETB'd and return Reanimate to your hand, leaving {B}{B}{B} floating.
Reanimate Archaeomancer and resolve the Inalla trigger, retrieving Burnt Offering and FInale of promise, {B} floating.
Sacrifice Archaeomancer to Burnt Offering, adding {R}{R}{B}{B}.
Cast Finale of Promise with X=1 targeting Entomb and Reanimate.
Entomb Shallow Grave and Reanimate Archaeomancer, {B} floating.
Resolve the Archaeomancer trigger returning Burnt Offering from your graveyard to your hand.
Sacrifice Archaeomancer to Burnt Offering, adding {B}{B}{B}{B}.
Resolve the Inalla trigger, making a token copy of Archaeomancer with haste and leaving {B}{B}{B} floating.
Return Shallow Grave with the token copy's ETB.
Cast Shallow Grave targeting Archaeomancer, leaving {B} floating.
Repeat steps 20-24 for infinite hasty Archaeomancers.

Infinite creature tokens with haste

Inalla, Archmage Ritualist

Spellseeker

Finale of Promise

Reanimate

Entomb

Archaeomancer

Unearth

Activate Cormela by paying {1} and tapping it, adding {U}{B}{R} that can only be spent to cast instant and sorcery spells.
Activate Phyrexian Altar by sacrificing Cormela, adding {1}.
Cormela dies, returning Shallow Grave from your graveyard to your hand.
Cast Shallow Grave by paying {1}{B}, putting Cormela from your graveyard onto the battlefield.
Repeat.

Infinite blue mana that can only be spent to cast instant and sorcery spells

Infinite red mana that can only be spent to cast instant and sorcery spells

Cormela, Glamour Thief

Phyrexian Altar

Activate Cormela by paying {1} and tapping it, adding {U}{B}{R} that can only be spent to cast instant and sorcery spells.
Activate Ashnod's Altar by sacrificing Cormela, adding {C}{C}.
Cormela dies, returning Shallow Grave from your graveyard to your hand.
Cast Shallow Grave by paying {1}{B}, putting Cormela from your graveyard onto the battlefield.
Repeat.

Infinite colorless mana

Ashnod's Altar

Activate Ashnod's Altar by sacrificing Corridor Monitor, adding {C}{C}.
Activate Isochron Scepter by paying {2} and tapping it, casting a copy of Shallow Grave without paying its mana cost.
Resolve Shallow Grave, returning Corridor Monitor from your graveyard to the battlefield.
Corridor Monitor enters the battlefield, untapping Isochron Scepter.
Repeat.

Isochron Scepter

Corridor Monitor

Activate Krark-Clan Ironworks by sacrificing Corridor Monitor, adding {C}{C}.
Activate Isochron Scepter by paying {2} and tapping it, casting a copy of Shallow Grave without paying its mana cost.
Resolve Shallow Grave, returning Corridor Monitor from your graveyard to the battlefield.
Corridor Monitor enters the battlefield, untapping Isochron Scepter.
Repeat.

Krark-Clan Ironworks

Combos with "Shallow Grave"