Ranger-Captain of Eos
Creature — Human Soldier Ranger
When this creature enters, you may search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Sacrifice this creature: Your opponents can't cast noncreature spells this turn.
Ryan Pancoast
Modern Horizons (MH1)
• #21Rulings
Your opponents may cast spells in response to the last ability of Ranger-Captain of Eos. The ability won’t affect those spells and it won’t affect spells that those players cast before you activated it. (In other words, the ability can’t be used to counter a spell.)
(wotc • 2019-06-14)
If a card in a player’s library has {X} in its mana cost, X is considered to be 0.
(wotc • 2019-06-14)
Rulings
Your opponents may cast spells in response to the last ability of Ranger-Captain of Eos. The ability won’t affect those spells and it won’t affect spells that those players cast before you activated it. (In other words, the ability can’t be used to counter a spell.)
(wotc • 2019-06-14)
If a card in a player’s library has {X} in its mana cost, X is considered to be 0.
(wotc • 2019-06-14)