Izzet goblin jank

As Arcane Adaptation enters the battlefield, choose a creature type.

Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Haste

{T}, Sacrifice Fanatical Firebrand: It deals 1 damage to any target.

Create a number of 1/1 red Goblin creature tokens equal to two plus the number of cards named Goblin Gathering in your graveyard.

When Goblin Instigator enters the battlefield, create a 1/1 red Goblin creature token.

({T}: Add {U}.)

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

({T}: Add {R}.)

{1}, {T}: Target player mills a card.

Tap four untapped Advisors you control: Target player mills twelve cards.

A deck can have any number of cards named Persistent Petitioners.

When Siege-Gang Commander enters the battlefield, create three 1/1 red Goblin creature tokens.

{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Sacrifice a Goblin: Add {R}.

({T}: Add {U} or {R}.)

As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.

{T}: Add {U} or {R}.

When Volley Veteran enters the battlefield, it deals damage to target creature an opponent controls equal to the number of Goblins you control.

When Wily Goblin enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")