An evicted demon inhabits a physical shell, gains limited enhanced abilities, and must drag another soul into Sheol to return.
Most demons cannot enter the world directly and need weakened bodies. Zombies are especially easy hosts, while fully dead corpses can also be taken less often by stronger demons.
Possessed shells become faster, stronger, and intelligent but remain constrained by the host body's physical limits and express only a fraction of the demon's true power. The system makes the possession recognizable when it occurs.
To earn return to Sheol, the demon must physically grapple a living victim. A portal then drags both down automatically, killing the victim and consuming the possessed body. Decapitation or inventory removal of new corpses reduces available hosts.
A zombie body filled with infernal light reaching for a living target as a portal opens beneath both.
The mechanic turns harmless weak undead into intelligent instant-death grapplers and changes safe corpse handling.