Stubborn Denial
Instant
Counter target noncreature spell unless its controller pays 
.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.
The Temur have no patience for subtlety.
James Ryman
Khans of Tarkir (KTK)
• #56Rulings
Some ferocious abilities that appear on instants and sorceries use the word “instead.” These spells have an upgraded effect if you control a creature with power 4 or greater as they resolve. For these, you only get the upgraded effect, not both effects.
(wotc • 2014-09-20)
Ferocious abilities of instants and sorceries that don’t use the word “instead” will provide an additional effect if you control a creature with power 4 or greater as they resolve.
(wotc • 2014-09-20)
Rulings
Some ferocious abilities that appear on instants and sorceries use the word “instead.” These spells have an upgraded effect if you control a creature with power 4 or greater as they resolve. For these, you only get the upgraded effect, not both effects.
(wotc • 2014-09-20)
Ferocious abilities of instants and sorceries that don’t use the word “instead” will provide an additional effect if you control a creature with power 4 or greater as they resolve.
(wotc • 2014-09-20)