Arjun, the Shifting Flame

Flying
Whenever you cast a spell, put the cards in your hand on the bottom of your library in any order, then draw that many cards.

Izzet Signet

{T}: Add one mana of any color in your commander's color identity.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

{T}: Add {C}{C}. Activate only if you control five or more lands.

You have no maximum hand size.
{T}: Add one mana of any color.

You have no maximum hand size.
{T}: Add {C}.

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.