Elden Ring - Shadow of the Erdtree | Messmer the Impaler boss fight w/2 cooperators on NG

Location: In Scadu Altus, at the very top of Shadow Keep

Two phase boss fight:
- Messmer the Impaler
- Base Serpent Messmer

Drops:
360,000 runes
Remembrance of the Impaler
Messmer's Kindling

Messmer the Impaler
"Messmer the Impaler is a Demigod Boss in Shadow of the Erdtree. He is the leader of the crusade against the Hornsent people, killing their Divine Beasts and burning the Tower Settlement. He is revealed to be Queen Marika's son, secreted away and abandoned in the Land of Shadow. In combat, he utilizes Fire-based Spells and a Greatspear. This is not an optional boss as players need to defeat him to advance in Shadow of the Erdtree."
https://eldenring.wiki.fextralife.com/Messmer+the+Impaler

Remembrance of the Impaler
"Remembrance of the Impaler is a Consumable Item in Elden Ring. It is a brand-new Remembrance in the Shadow of the Erdtree DLC. Most Consumables grant various effects such as restorative properties for recovering HP, removing certain negative status effects or applying temporary buffs and debuffs, while others can be thrown at enemies to deal damage."
https://eldenring.wiki.fextralife.com/Remembrance+of+the+Impaler

Messmer's Kindling
"Messmer's Kindling is a Key Item in Elden Ring. It is a brand new Key Item in the Shadow of the Erdtree DLC. Key Items in Elden Ring include a wide variety of items found in specific locations or are given by a related NPCs which are used to unlock areas, quests, and to further progress the game's story."
https://eldenring.wiki.fextralife.com/Messmer's+Kindling