Bruna, Light of Alabaster

Flying, vigilance
Whenever Bruna attacks or blocks, you may attach to it any number of Auras on the battlefield and you may put onto the battlefield attached to it any number of Aura cards that could enchant it from your graveyard and/or hand.

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Dream Halls

Rather than pay the mana cost for a spell, its controller may discard a card that shares a color with that spell.