Spell Pierce

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

Deceiver Exarch

Flash (You may cast this spell any time you could cast an instant.)
When Deceiver Exarch enters the battlefield, choose one —
• Untap target permanent you control.
• Tap target permanent an opponent controls.

Island

Electrolyze

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

Mountain

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Mana Leak

Counter target spell unless its controller pays {3}.

Unsubstantiate

Return target spell or creature to its owner's hand.

Zealous Conscripts

Haste
When Zealous Conscripts enters the battlefield, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Counterspell

Pestermite

Flash
Flying
When Pestermite enters the battlefield, you may tap or untap target permanent.