Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.
Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy. Partner
You may have Sakashima enter as a copy of another creature you control, except it has Sakashima's other abilities. The "legend rule" doesn't apply to permanents you control. Partner
When you cast this spell, exile two target permanents. Indestructible Whenever Ulamog attacks, defending player exiles the top twenty cards of their library.