Skulls of the Serpent
Over 200 years ago, Darius was a member of House Sol. When his brother gained both his fame, fortune, and betrothed, Darius renounced his family and turned to House Thrune, making bargains with Asmodeus to gain fell powers and extended life.
For the next two centuries, Darius helped rule Cheliax as the most powerful Hellknight of the nation.
Eventually, Darius was convinced to renounced House Thrune by Cacciaguida Roux, a prisoner and member of the Bellflower Network. When Darius turned his back on Asmodeus, he found that his powers had all but vanished, and he restarted his life as a guard for House Roux and the Bellflouwer Network, taking the name of Ren:.