Coruscation Mage

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Dockside Extortionist

When this creature enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Stormsplitter

Haste
Whenever you cast an instant or sorcery spell, create a token that's a copy of this creature. Exile that token at the beginning of the next end step.

Sol Ring

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, this artifact deals 3 damage to you.
{T}: Add {C}{C}.

Izzet Signet

Arcane Signet

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

Ghyrson Starn, Kelermorph

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Three Autostubs — Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson Starn deals 2 damage to that permanent or player.