Name: Wall of Flesh
Circles: Death, ?
Description: A spell that creates a wall of flesh around the targeted city. If the wall is breached, it heals the breach in a few turns. The wall may try to envelop enemy units in base contact with it and deal some damage.
I think we would all like an indestructible attack wall, but this might be OP unless it has some serious drawbacks, like Fire does 2x damage and prevents regen.