Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Bust

Boom

Destroy target land you control and target land you don't control.

Boom // Bust

Mana Tithe

Counter target spell unless its controller pays {1}.

Stoneforge Mystic

When Stoneforge Mystic enters, you may search your library for an Equipment card, reveal it, put it into your hand, then shuffle.
{1}{W}, {T}: You may put an Equipment card from your hand onto the battlefield.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Solitude

Flash
Lifelink
When Solitude enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Fury

Double strike
When Fury enters, it deals 4 damage divided as you choose among any number of target creatures and/or planeswalkers.
Evoke—Exile a red card from your hand.

Prismatic Ending

Converge — Exile target nonland permanent if its mana value is less than or equal to the number of colors of mana spent to cast this spell.

Crack the Earth

Kaldra Compleat

Living weapon
Indestructible
Equipped creature gets +5/+5 and has first strike, trample, indestructible, haste, and "Whenever this creature deals combat damage to a creature, exile that creature."
Equip {7}