Jeskai Ascendancy and Sorcerer Class on the battlefield.
Sorcerer Class is at least level two.
You control at least four creatures without summoning sickness.
Steps
Activate four creatures you control by tapping them, adding ({3} magic symbol) ({R} magic symbol) that can only be spent to cast instant and/or sorcery spells, or to gain a Class level.
Cast Haze of Rage with buyback by paying ({3} magic symbol) ({R} magic symbol) , triggering Jeskai Ascendancy's first and second abilities, Haze of Rage's storm ability, and Sorcerer Class's third ability if it is level three.
Resolve the Sorcerer Class trigger, if applicable, causing Haze of Rage to deal an amount of damage to each opponent equal to the number of instants and sorceries you've cast this turn.
Resolve the Haze of Rage trigger, creating a copy of it for each spell you've cast before it this turn.
Resolve the first Jeskai Ascendancy trigger, giving creatures you control +1/+1 until end of turn and untapping them.
Resolve the second Jeskai Ascendancy trigger, allowing you to loot.
Resolve all Haze of Rages, causing creatures you control to get +1/+0 for each Haze of Rage, and returning the original Haze of Rage to your hand.
Repeat.
If you control five or more creatures without summoning sickness, this combo nets near-infinite mana.
Results
Infinite draw triggers.
Infinite looting.
Infinite self-discard triggers.
Near-infinite blue mana that can only be spent to cast instant and/or sorcery spells.
Near-infinite damage.
Near-infinitely large creatures until end of turn.
Near-infinite magecraft triggers.
Near-infinite red mana that can only be spent to cast instant and/or sorcery spells.