Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Meandering River

Meandering River enters tapped.
{T}: Add {W} or {U}.

Arcanum Wings

Enchant creature
Enchanted creature has flying.
Aura swap {2}{U} ({2}{U}: Exchange this Aura with an Aura card in your hand.)

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

Slither Blade

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Woodland Stream

Woodland Stream enters tapped.
{T}: Add {G} or {U}.

Gladecover Scout

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Creeping Tar Pit

Creeping Tar Pit enters tapped.
{T}: Add {U} or {B}.
{1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

Unsummon

Return target creature to its owner's hand.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Colossification

Enchant creature
When Colossification enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Island

Academy Researchers

When Academy Researchers enters, you may put an Aura card from your hand onto the battlefield attached to Academy Researchers.