Skaoi's Amulet

When this artifact enters the battlefield, if Skaoi is in the battlefield put +2/+2 counters on all blue and white Elder Dragons and +1/+1 counters on all Skaoi's foot soldiers in the battlefield.
{u}{u}{w}: Skaoi's amulet becomes an instant that makes all of Skaoi's foot soldiers hexproof until end of turn. After this ability is used Skaoi's amulet returns back into its owners hand.