Death doesn't have to be the end of it all, especially not in a fantasy setting. While the basic rules cover certain necromantic spells, there's not a whole ton of it going around in detail in 5th Edition. That's where Whispers of Persephone come in. It's a new Necromancy Sourcebook that's up on Kickstarter now. (This post typed while Love You To Death plays on Pandora. Seemed fitting).