Gift of Polukranos

Choose a creature you control and put X +1/+1 counters on it. Then, if that creature is a Hydra,
it deals X damage divided as you choose among
any number of creatures your opponents control.
Each of those creatures deals damage equal to its
power to the chosen creature.
An incantation known only by the Reincarnated can
grow any hydra to the size of the World Eater herself.