Erantus, the Shield of Adera

Legendary creatures you control have vigilance.
Other creatures you control get +1/+1 for each legendary creature you control.
{g}{g}{t}: The next time damage would be dealt to
you or permanents you control this turn, prevent
that damage. Deal damage to Erantus, the Shield
of Adera equal to half the damage prevented with
this ability, rounded up.