December 9, 2014 9:11 p.m.
Kiln Fiend's ability triggers when you cast a spell. So it always ends up on top of, and resolving first, before the spell that triggers it resolves. To be clear, Ferocious doesn't trigger. It's a check that happens as the spell is resolving. As long as Kiln Fiend is still on the field and its trigger successfully resolved it will be at least a 4 power creature and thus you'll get the Ferocious effect of Stubborn Denial.
December 9, 2014 9:15 p.m.
Ooh, I thought so; A 1-mana situational counterspell for my Izzet pump deck :)