Sergeant Gilbert is an NPC in BLACKSOULS 2 you can find inside the Charles Tavern, located in Lutwidge Town. He’s sitting at one of the tables, and you can talk to him although the things he says don’t make too much sense.
Gilbert is very close with Sullivan, as they’re most likely inspired by Gilbert and Sullivan – a Victorian-era theatrical partnership of two dramatists, W. S. Gilbert, and Arthur Sullivan.
You can easily kill him if you want to.
Meeting with Sullivan
If you go to the western side of Lutwidge Town, after you hit 5 Progression Points or more, you’ll see Gilbert and Sullivan having fun with each other.
