How does the Shrine of the Gunbringer work?

Solution 1:

I've used the shrine with my brother in co-op and can confirm that it works with putting players in the pit.

Firstly, you only get one lever pull when the zone loads, so it's important not to pull it before your sacrifice is in. Once they are in, pull the lever, and the top shuts. Flames turn on inside the pit and the sacrifice (slowly) dies. Once they die, the shrine provides some loot.

We did this around level 15 on the first playthrough, and the loot wasn't very good. I would be interested to know if the loot gets better on playthrough 2 or by putting more players in the pit. I'm not sure if this works on NPCs, if you could even manage to get one in there!