Dina, Soul Steeper

Whenever you gain life, each opponent loses 1 life.
{1}, Sacrifice another creature: Dina gets +X/+0 until end of turn, where X is the sacrificed creature's power.

Sphere Grid

Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.
Unlock Ability — Creatures you control with +1/+1 counters on them have reach and trample.

Mjölnir, Storm Hammer

When Mjölnir enters, attach it to target legendary creature you control.
Whenever equipped creature attacks, tap target creature defending player controls and put a stun counter on it. Then Mjölnir deals damage to each opponent equal to the number of tapped creatures that opponent controls.
Equip {4}

One with Nature

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lisette, Dean of the Root

Whenever you gain life, you may pay {1}. If you do, put a +1/+1 counter on each creature you control and those creatures gain trample until end of turn.

Valentin, Dean of the Vein

Menace, lifelink
If a nontoken creature an opponent controls would die, exile it instead. When you do, you may pay {2}. If you do, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Valentin, Dean of the Vein // Lisette, Dean of the Root

Excalibur II

Whenever you gain life, put a charge counter on Excalibur II.
Equipped creature gets +1/+1 for each charge counter on Excalibur II.
Equip {3}

Sol Ring

Vraska Joins Up

When Vraska Joins Up enters, put a deathtouch counter on each creature you control.
Whenever a legendary creature you control deals combat damage to a player, draw a card.

Creeping Bloodsucker

At the beginning of your upkeep, this creature deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Master's Guidance

Whenever you attack with two or more legendary creatures, put a +1/+1 counter on each of up to two target attacking creatures.
At the beginning of your end step, if you control a creature with power 4 or greater, draw a card.

Blood Researcher

Menace (This creature can't be blocked except by two or more creatures.)
Whenever you gain life, put a +1/+1 counter on this creature.

Nasty End

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards. If the sacrificed creature was legendary, draw three cards instead.

Tempt with Treats

Create a Food token. (Then exile this card. You may cast the creature later from exile.)

Gumdrop Poisoner

Lifelink
When this creature enters, up to one target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn.

Gumdrop Poisoner // Tempt with Treats

Starscape Cleric

Offspring {2}{B} (You may pay an additional {2}{B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
This creature can't block.
Whenever you gain life, each opponent loses 1 life.

Trudge Garden

Whenever you gain life, you may pay {2}. If you do, create a 4/4 green Fungus Beast creature token with trample.

Gourmand's Talent

(Gain the next level as a sorcery to add its ability.)
During your turn, artifacts you control are Foods in addition to their other types and have "{2}, {T}, Sacrifice this artifact: You gain 3 life."
{2}{G}: Level 2
Whenever you gain life for the first time each turn, create a 3/3 green Raccoon creature token.
{3}{G}: Level 3
Whenever you gain life for the first time each turn, put a +1/+1 counter on each creature you control.

Sixth Sense

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, you may draw a card."

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach this Equipment to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Wrecking Ball Arm

Equipped creature has base power and toughness 7/7 and can't be blocked by creatures with power 2 or less.
Equip legendary creature {3}
Equip {7}

Keen Sense

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Bloodthirsty Aerialist

Flying
Whenever you gain life, put a +1/+1 counter on this creature.

Ace's Baseball Bat

Equipped creature gets +3/+0.
As long as equipped creature is attacking, it has first strike and must be blocked by a Dalek if able.
Equip legendary creature {1}
Equip {3}