Horizon Scholar | Magic: The Gathering
Formats Horizon Scholar is Legal in
Official Oracle Text for Horizon Scholar
When Horizon Scholar enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)
Official Rulings for Horizon Scholar
9/15/2013 : You choose how to order cards returned to your library after scrying no matter where you put them.
9/15/2013 : You perform the actions stated on a card in sequence. For some spells and abilities, that means you’ll scry last. For others, that means you’ll scry and then perform other actions.
9/15/2013 : Scry appears on some spells and abilities with one or more targets. If all of the spell or ability’s targets are illegal when it tries to resolve, it will be countered and none of its effects will happen. You won’t scry.