Lethal Legacy

Enchanted creature has soulbond and "As long as this creature is paired with another creature, each of those creatures has deathtouch."
When enchanted creature dies, you may attach Lethal Legacy to a creature it's paired with.
"When you promise that you're his, shivering and sighing, and he swears his love for you is infinite, undying, lady take a note -- one of you is lying."