Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Jin Sakai, Ghost of Tsushima

Whenever Jin Sakai deals combat damage to a player, draw a card.
Whenever a creature you control attacks a player, if no other creatures are attacking that player, choose one —
• Standoff — It gains double strike until end of turn.
• Ghost — It can't be blocked this turn.

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Summon: Primal Odin

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Gungnir — Destroy target creature an opponent controls.
II — Zantetsuken — This creature gains "Whenever this creature deals combat damage to a player, that player loses the game."
III — Hall of Sorrow — Draw two cards. Each player loses 2 life.

Medomai the Ageless

Flying
Whenever Medomai deals combat damage to a player, take an extra turn after this one.
Medomai can't attack during extra turns.

Phage the Untouchable

When Phage enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Vorpal Sword

Equipped creature gets +2/+0 and has deathtouch.
{5}{B}{B}{B}: Until end of turn, this Equipment gains "Whenever equipped creature deals combat damage to a player, that player loses the game."
Equip {B}{B}