>>96064892
Pretty sure the intro story to Dawn of War Black Crusade's Chaos campaign outright shows an insane psyker's mental breakdown until he turned himself into a living portal to the Warp as part of a ritual to bring back Eliphas the Inheritor, as well as being sucked into the Warp being an exceptionally rare miscast possibility in the Dark Heresy line of rpgs. So it is something that can happen in the setting.