Aging
Aging is a special ability of Ghost Dragons. It causes maximum health of every creature in the target stack to be halved. The effect of aging effect can only be removed with the Cure spell. The effect lasts for 3 combat rounds.
The aging takes effect after a stack of Ghost Dragons have attacked target creature stack and before the stack has chance to retaliate. Any health lost before the aging takes effesct remains lost (e.g. Angel has maximum health of 200. It is missing 60 health points and has 140 points remaining when aged. It will have 40 health left, which by calculation is 200/2 = 100 → 100-60 = 40.)
The effect of aging has multiplicative effect with Wyvern Monarchs' poisonous ability. This means, that the creature stack's health could potentially be quartered.
Creatures with aging special ability:
Creatures with immunity to aging: Undead:
Skeletons and Skeleton Warriors
Walking Dead and Zombies
Wights and Wraiths
Vampires and Vampire Lords
Liches and Power Liches
Black and Dread Knights
Bone and Ghost Dragons
Mummies 
Elementals:
