Scion of Seas

Splurge 3 (You may return 3 lands you control to their owner's hands rather than pay this spell's mana cost.)

When Scion of Seas attacks, you may reveal 3 islands from your hand. If you do, it can't be blocked this turn.
Whenever one or more creature attack you, you may reveal 3 islands from your hand. If you do, untap each Elemental you control.