Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

IDW Comics Inserts

Time Spiral

Flash (You may play this spell any time you could play an instant.)
When Voidmage Husher comes into play, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you play a spell, you may return Voidmage Husher to its owner's hand.

Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.