Ruby Medallion

Red spells you cast cost {1} less to cast.

Glimpse the Impossible

Exile the top three cards of your library. You may play those cards this turn. At the beginning of the next end step, if any of those cards remain exiled, put them into your graveyard, then create a 0/1 colorless Eldrazi Spawn creature token for each card put into your graveyard this way. Those tokens have "Sacrifice this creature: Add {C}."

Boltwave

Boltwave deals 3 damage to each opponent.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Pyretic Ritual

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Razorkin Needlehead

Razorkin Needlehead has first strike during your turn.
Whenever an opponent draws a card, Razorkin Needlehead deals 1 damage to them.

Volcanic Island

Niv-Mizzet, Visionary

Flying
You have no maximum hand size.
Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mountain

Flame Rift

Flame Rift deals 4 damage to each player.

Island

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.