Elden Ring PC | Commander O'Neal boss fight co-op w/2 summoned players & an uninvited invader on NG

Drops:
10,800 runes
Commander's Standard
Unalloyed Gold Needle

Commander O'Neil
"Commander O'Neil is a Great Enemy Boss in Elden Ring. Commander O'Neil is a human who wields a halberd with a battle standard and summons aid from ghostly warriors. He can be found at the heart of the Swamp of Aeonia in eastern Caelid. This is an optional boss as players are not required to defeat him in order to advance in Elden Ring, but he provides useful items and Runes upon defeat."
https://eldenring.wiki.fextralife.com/Commander+O'Neil