Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Harbor Serpent

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
This creature can't attack unless there are five or more Islands on the battlefield.

Death Cultist

Sacrifice this creature: Target player loses 1 life and you gain 1 life.

Bile Urchin

Sacrifice this creature: Target player loses 1 life.

Ancestral Recall

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Mind Sculpt

Blessing of Leeches

Flash
Enchant creature
At the beginning of your upkeep, you lose 1 life.
{0}: Regenerate enchanted creature.