Child of Night

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Geth's Verdict

Target player sacrifices a creature of their choice and loses 1 life.

Swamp

Ajani's Pridemate

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

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Sign in Blood

Target player draws two cards and loses 2 life.

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Murder

Ajani's Mantra

At the beginning of your upkeep, you may gain 1 life.

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform Chalice of Life.