Seed of Destiny:

Once per war session, the wielder may sacrifice a unit at full HP to heal all other non-ruler units by half of their maximum HP, rounded up. When this occurs, reduce Food storage by 2d4+1. If this reduction brings Food storage to 0, lose 1 level of Stability. If a mercenary company uses this effect, there is a 50% chance to lose 1 level of Renown.