Riva was born of the Shadowfell dedicated his life to serving the Raven Queen. His adventures led him out into the Material plane. His dedication made him a lethal fighter.
He dallied with many women. Some in the fell itself, bearing children to the Shadar-kai. And others brought death upon them and took them to the Raven Queen. Aelfwyn was one such sole with whom he’d tried to lure into the realm, but the Material Gods had other plans.
The good doctor’s proximity to the Leech allowed her survival and the birth of a half-elf creation of Shadar-kai, the only half child Riva knew of. He fled the hovel she dwelt and for once failed his Queen. He sought refuge in the Material Plane, continuing his journey for Fallen Souls but never returning home.
Over the centuries, Riva founded many places and many guilds. Only one survived the plagues and ravishing of the Material Plane — Macabre Genesis. A criminal organization shrouded in the light of common mercantile business and shipping. It was the Macabre’s business to find and extort and distribute things to bring the Raven Queen souls. Including helping the Soul Takers in their jobs and entertainments.
The guild grew over the centuries and is established across the known world. Riva owes much to the Raven Queen.
The best place to find souls for the Raven Queen is those who find their wealths and playthings with the sins of the Gods of the Material realm. Riva enjoys toying with his marks, building them up only to tear them down. Foiling their plans as they try to take advantage of him. It’s his favorite game to play.