A virus (for lack of more accurate term at the present time) affects a rather large portion of the human population, roughly 30%. A few hours after death, a new humanoid organism called a remnant emerges from the corpse. Depending on the specific strain and the condition of the body after death, the remnant contains some of the memories and mannerisms of the original host. The remnant isn't a true replica of the host, but rather a poor copy. The mannerisms and memories are often jumbled and slightly flawed. The remnant also fixates upon one facet of the host's life. For instance, a pilot would produce a remnant who's sole fixation would be upon flying to the extent of little else other than maintaining its existence. The virus is an artificial virus created originally for cancer treatments but converted towards rather obvious military applications.
What I'm lacking are details. All of this is going to be glossed over anyway and the focus is on the characters themselves rather than the mechanics of the virus, but I'd at least like to make an attempt at plausibility. For instance: What are some universal signs of death? Like, what would make for a good trigger for the virus? Is a virus good to work with anyway? Would an organic nanobot work better? Like a virus designed from the dna up to perform a specific function? How would memory transfer work?
And on a random tangent, salty corn chips or doritos with your bean dip?