Disallow {1}{U}{U}

Notes and Rules Information for Disallow:

• Activated abilities are written in the form "Cost: Effect." Some keyword abilities, such as equip and crew, are activated abilities and will have colons in their reminder texts. (2017-02-09)
• Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]." Some keyword abilities, such as prowess and fabricate, are triggered abilities and will have "when," "whenever," or "at" in their reminder text. (2017-02-09)
• If you counter a delayed triggered ability that triggers at the beginning of the "next" occurrence of a specified step or phase, that ability won't trigger again the following time that phase or step occurs. (2017-02-09)

• An activated mana ability is one that could add mana as it resolves, doesn't have a target, and isn't a loyalty ability. A triggered mana ability is one that could add mana and triggers on an activated mana ability. (2017-02-09)
• Abilities that create replacement effects, such as a permanent entering the battlefield tapped or with counters on it, can't be targeted. Abilities that apply "as [this creature] enters the battlefield" are also replacement effects and can't be targeted. (2017-02-09)
• There are many important moments in the story, but the most crucial—called "story spotlights"—are shown on cards. These cards have the Planeswalker symbol in their text box; this symbol has no effect on gameplay. You can read more about these events in the official Magic fiction at www.mtgstory.com. (2018-01-19)