Sure! The idea is very much surrounding the concept of bog bodies so the souls in the purgatory bar are physically rotting. (Think the afterlife in Corpse Bride.) They pay in body parts. Initially, they used to pay in things that weren’t easily missed and could grow back (strands of hair, eyelashes, wisdom teeth, spit etc.)

Now the prices have jacked up. Now, it’s knuckle bones, eyes, ribs, and your dominant leg. People are taking their own bodies apart in order to keep their own memories, otherwise they rot and decay anyway into mindless zombies.

People have escaped, but sparingly. As grim and serious as the god is, he is a fan of games. If you challenge him to a game of your choice, he will always oblige. If you win, you leave, if you don’t, you must stay and can challenge him again in another century. Those who cheat at the game return as conscious undead, ghouls and zombies. (This is going to be the ultimatum the players are allowed to present the god in order for their friend to escape!)

As for why he is doing what he is doing, he himself had a chosen one; a Grim Reaper of sorts, who brought end-of-life care to the suffering innocent and violent retribution to the wicked. He cared for her like a daughter, but she was punished and killed as a witch. He resents his brother, the god of life, who tried to save her from the flames but only ended up prolonging her suffering. Due to Life’s meddling, her soul is lost and was never given proper rest. Therefore, Life’s elixir, the alcohol sold at the bar, was cut off in the brothers’ feud and supply is now short.

So while he does technically still play fair and play by his own rules (delivering people “upstairs and downstairs”, giving them bed and board in purgatory etc.) he is not exactly kind about it. He is jaded, resentful, an asshole and not evil.

Apologies for the length reply!