Ferocious + Prowess

[Skullguy725]

So I have a {Monastery Mentor} on the field, and I've just cast {Murderous cut} triggering Mentor's prowess and making it a 3/3
I go to combat, my opponent casts {Heros downfall} targeting the mentor. I respond by casting {Stubborn Denial} to counter downfall.

Does monastery mentor's prowess make him a 4/4 in time to trigger the ferocious part of stubborn denial?

[Cender]

So I have a {Monastery Mentor} on the field, and I've just cast {Murderous cut} triggering Mentor's prowess and making it a 3/3
I go to combat, my opponent casts {Heros downfall} targeting the mentor. I respond by casting {Stubborn Denial} to counter downfall.

Does monastery mentor's prowess make him a 4/4 in time to trigger the ferocious part of stubborn denial?

In the example you give, yes, because the stack with murderous cut resolves, giving one prowess trigger, and the other stack will look like this:
Top - resolves first -
{monastery mentor} 1/1 monk trigger
{Monastery mentor} prowess trigger
{stubborn Denial}
{Hero's Downfall}

The two mentor triggers can be stacked as you please, but they both resolve before your stubborn denial checks power level for its ferocious replacement effect.

[Skullguy725]

So I have a {Monastery Mentor} on the field, and I've just cast {Murderous cut} triggering Mentor's prowess and making it a 3/3
I go to combat, my opponent casts {Heros downfall} targeting the mentor. I respond by casting {Stubborn Denial} to counter downfall.

Does monastery mentor's prowess make him a 4/4 in time to trigger the ferocious part of stubborn denial?

In the example you give, yes, because the stack with murderous cut resolves, giving one prowess trigger, and the other stack will look like this:
Top - resolves first -
{monastery mentor} 1/1 monk trigger
{Monastery mentor} prowess trigger
{stubborn Denial}
{Hero's Downfall}

The two mentor triggers can be stacked as you please, but they both resolve before your stubborn denial checks power level for its ferocious replacement effect.

Thanks! Glad to hear that