<div class="floatleft">(https://i.pinimg.com/originals/c4/4f/36/c44f365ffaa2f6be069e0f2444d63ee1.jpg)</div>As Jerion does his question, it's not matron mother herself but the archmage who spoke and replied; "I can answer that Jerion; a magical ritual which originally was a divine spell used by priestess who serves goddess of love and passion. A marriage ritual bind life and soul into one entity. I modified the original ritual a arcane bonding ritual, very similar to powerful binding spell but a variant. Then sprinkle in some condittions and curse of instant death upon sunlight by greater curse magic, then you have it basically. Albeit it has some disadvantages to keep both slaves alive, when other is in actual hazardous field work. But it extends lifespan of the human similar to elf's or rather splits it evenly equal halves and it return gives them both a eternal youth as well. So when they die at end of natural lifespan, it happens same time. The souls bound together it's just naturall they depart together in afterlife as link remains even when they die. In case ressurection need ressurect both and not the other. Only a god can sever the link now and very likely lead these twinned souls reborn as twins or similar entities. Naturally spell only works mortal races and entities, so cannot combine immortal with a mortal. Also outsiders bodies and souls are one and same entity. But still, handy ritual with several possible purposes."