We were playing this card for long time ago, I have a question about how to use the cascade ability correctly. My friend exile cards until he decide which card he wants to exile and use, I thought it was the first exiled card that cost less than etherium-horn sorcerer. Who is right???
The definition of cascade is “When you cast this spell, exile cards from the top of your library until you exile a nonland card whose converted mana cost is less than this spell’s converted mana cost. You may cast that card without paying its mana cost. Then put all cards exiled this way that weren’t cast on the bottom of your library in a random order.” (CR 702.84 Cascade)
If you direct your attention to the first sentence, you'll see that the player who casts Etherium-Horn Sorcerer must stop at the first card with lesser converted mana cost. The only choice is whether to cast that card, or put it on the bottom of the library in a random order with the others.