Winslow was killed by Orin the Red. His body was used as a component of Orin's "art" as an effigy to Abazigal, a Bhaalspawn defeated more than a century ago, along with the body of Katebee Pol.
Winslow's in-game model, as well as the models of Echo of Abazigal (Abazigal's ghost at the Murder Tribunal) and Goxxoon (another dead Dragonborn used to depict Abazigal in the Undercity Ruins), is designed to copy Abazigal's image from the previous Baldur's Gate games.
