Activate Ashnod's Altar by sacrificing Scampering Scorcher, adding {C}{C}.
Scampering Scorcher dies, triggering Nim Deathmantle, causing you to pay {4} to return Scampering Scorcher from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Scampering Scorcher enters the battlefield, creating two 1/1 Elemental creature tokens and giving Elementals you control haste until end of turn.
Activate Ashnod's Altar by sacrificing an Elemental token, adding {C}{C}.
Repeat.

Infinite colorless mana

Infinite creature tokens with haste

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Nim Deathmantle

Ashnod's Altar

Scampering Scorcher

Activate Horde of Notions by paying {5}, casting Scampering Scorcher from your graveyard without paying its mana cost.
When Scampering Scorcher enters the battlefield, it triggers, creating two 1/1 Elemental creature tokens and giving Elementals you control haste until end of turn.
Activate Ashnod's Altar three times by sacrificing Scampering Scorcher and two Elementals, adding six {C}.
Repeat.

Combos with "Scampering Scorcher"