Ornithopter

Mountain

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Memnite

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Disciple of the Vault

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Island

Channel

Until end of turn, any time you could activate a mana ability, you may pay 1 life. If you do, add {C}.

Flash

You may put a creature card from your hand onto the battlefield. If you do, sacrifice it unless you pay its mana cost reduced by up to {2}.