Mana Leak

Counter target spell unless its controller pays {3}.

Twinning Staff

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Icy Blast

Tap X target creatures.
Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Counterspell

Metallurgic Summonings

Whenever you cast an instant or sorcery spell, create an X/X colorless Construct artifact creature token, where X is that spell's mana value.
{3}{U}{U}, Exile this enchantment: Return all instant and sorcery cards from your graveyard to your hand. Activate only if you control six or more artifacts.

Elementalist's Palette

Whenever you cast a spell with {X} in its mana cost, put two charge counters on this artifact.
{T}: Add one mana of any color.
{T}: Add {C} for each charge counter on this artifact. Spend this mana only on costs that contain {X}.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Shenanigans

Destroy target artifact.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Brudiclad, Telchor Engineer

Creature tokens you control have haste.
At the beginning of combat on your turn, create a 2/1 blue Phyrexian Myr artifact creature token. Then you may choose a token you control. If you do, each other token you control becomes a copy of that token.

Izzet Signet

Arcane Signet

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

Storm-Kiln Artist

This creature gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

Sol Ring

Shark Typhoon

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle this card, create an X/X blue Shark creature token with flying.

Ghired's Belligerence

Ghired's Belligerence deals X damage divided as you choose among any number of target creatures. Whenever a creature dealt damage this way dies this turn, populate. (Create a token that's a copy of a creature token you control.)

Zaffai, Thunder Conductor

Magecraft — Whenever you cast or copy an instant or sorcery spell, scry 1. If that spell's mana value is 5 or greater, create a 4/4 blue and red Elemental creature token. If that spell's mana value is 10 or greater, Zaffai deals 10 damage to an opponent chosen at random.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Thought Vessel

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

Brass's Bounty

For each land you control, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")