Accumulated Knowledge

Draw a card, then draw cards equal to the number of cards named Accumulated Knowledge in all graveyards.

Volcanic Hammer

Volcanic Hammer deals 3 damage to any target.

Electrolyze deals 2 damage divided as you choose among one or two targets.
Draw a card.

Counter target spell unless its controller pays {3}.

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever Ophidian attacks and isn't blocked, you may draw a card. If you do, Ophidian assigns no combat damage this turn.

Counter target spell. Ionize deals 2 damage to that spell's controller.

Enchant creature
You control enchanted creature.

Flying
Whenever Thundering Djinn attacks, it deals damage to any target equal to the number of cards you've drawn this turn.

{U}, {T}: Draw two cards.
{R}, {T}, Discard a card: Mercurial Chemister deals damage to target creature equal to the discarded card's mana value.