Activate Lord of the Forsaken's first ability by paying and sacrificing Oathsworn Vampire.
When Oathsworn Vampire dies, Pitiless Plunderer and Elas il-Kor's second ability trigger twice.
Resolve both Pitiless Plunderer triggers, creating two Treasure artifact tokens.
Resolve both Elas il-Kor triggers, causing each opponent to lose 2 life.
Resolve the Lord of the Forsaken ability from step 1, causing target player to mill three cards.
Activate Lord of the Forsaken's second ability by paying 1 life, adding C that can only be spent to cast a spell from your graveyard.
Activate both Treasures by tapping and sacrificing them, adding .
Cast Oathsworn Vampire from your graveyard by paying 1.
When Oathsworn Vampire enters the battlefield, Elas il-Kor's first ability triggers, causing you to gain 1 life.
Repeat.
This elegant loop feeds entirely on itself by turning the act of a creature's demise into an engine of endless rebirth and devastation. Pitiless Plunderer funds the loop by spitting out Treasure tokens whenever a creature perishes, while Teysa Karlov doubles up every single death-related trigger to maximize your momentum. Every time Oathsworn Vampire hits the graveyard, Elas il-Kor, Sadistic Pilgrim drains your opponents while setting up the life gain you need to cast the vampire right back out of your graveyard. Lord of the Forsaken acts as the ultimate catalyst, both sacrificing your creatures to fuel your graveyard shenanigans and converting your life total into the colorless mana required to cast spells from the dead.