Sylvan Safekeeper

Sacrifice a land: Target creature you control gains shroud until end of turn. (It can't be the target of spells or abilities.)

Wirewood Symbiote

Return an Elf you control to its owner's hand: Untap target creature. Activate only once each turn.

Breya, Etherium Shaper

Thopter

When Breya enters, create two 1/1 blue Thopter artifact creature tokens with flying.
{2}, Sacrifice two artifacts: Choose one —
• Breya deals 3 damage to target player or planeswalker.
• Target creature gets -4/-4 until end of turn.
• You gain 5 life.

Energy Reserve

Guide of Souls

A-Guide of Souls

Whenever another creature you control enters, you gain 1 life and get {E} (an energy counter).
Whenever you attack, you may pay {E}{E}{E}. When you do, put two +1/+1 counters and a flying counter on target attacking creature. It becomes an Angel in addition to its other types.

Kaalia of the Vast

Flying
Whenever Kaalia attacks an opponent, you may put an Angel, Demon, or Dragon creature card from your hand onto the battlefield tapped and attacking that opponent.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Jet Medallion

Black spells you cast cost {1} less to cast.

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Pearl Medallion

White spells you cast cost {1} less to cast.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Barbarian Ring

{T}: Add {R}. This land deals 1 damage to you.
Threshold — {R}, {T}, Sacrifice this land: It deals 2 damage to any target. Activate only if there are seven or more cards in your graveyard.

Eldrazi Spawn

Drownyard Lurker

Vigilance
When you cast or cycle Drownyard Lurker, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this token: Add {C}."
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)

Hexgold Slith

When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, it gains first strike until end of turn.
Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.

Modern Horizons 3