http://www.kundalini-teacher.com/awakening/shamn.html

even though you’re not talking about becoming the grim reaper specifically, this part still seems like it might be pretty applicable:

“One aspect of Shamanic training is meeting, integrating the archetype of death itself. It often first shows up as the “Portal Guardian of the dream time” a great, vaguely human shaped black shadow being, that reflects your fear back multiplied with destructive force. It may also show up as the typical “death” image, a cloaked being with a cowl, no face. You may face it over and over, being utterly destroyed in dreams and visions over and over, till you learn to approach it with unconditional love… at which point you enter the next phase, you become that being, your consciousness a passenger within it, as it goes about reflecting fear and destroying.”