Activate Lord of the Forsaken's first ability by paying and sacrificing Oathsworn Vampire.
When Oathsworn Vampire dies, Pitiless Plunderer and Blood Artist trigger twice.
Resolve both Pitiless Plunderer triggers, creating two Treasure artifact tokens.
Resolve both Blood Artist triggers, causing target opponent to lose 2 life and you to gain 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.
Repeat.
This loop transforms a modest sacrifice outlet into an engine of endless doom by taking advantage of overlapping replacement effects and mana production. Lord of the Forsaken feeds Oathsworn Vampire into its mill ability, which triggers Pitiless Plunderer to spawn Treasure tokens and Blood Artist to drain the opposition. Meanwhile, Drivnod, Carnage Dominus doubles every single one of those death triggers while simultaneously ensuring the board state stays resilient through its own activated protection. Because Oathsworn Vampire can be recast directly from the graveyard utilizing life paid to Lord of the Forsaken's mana ability and the Treasures generated by Pitiless Plunderer, Blood Artist's constant life-gaining triggers ensure you always meet the condition to repeat the entire gruesome cycle indefinitely.