I'm just wondering if this combination seems legitimate to anyone:
At level 11, the Pistolero Gunslinger gets this deed:
Twin Shot Knockdown (Ex)
At 11th level, when the pistolero hits a single target with two or more one-handed firearm attacks during her turn, she can spend 1 grit point to knock the target prone. She can choose to spend the grit point after the attacks are made.
Mythic Champion Tier 3 allows taking of this path ability:
Unstoppable Shot (Ex)
You can use a ranged or thrown weapon to make a single powerful shot that shoots through all creatures in a line. As a standard action, make a single ranged attack roll and resolve the attack against all targets in a straight line up to the maximum range of your weapon, stopping at any barrier the attack couldn't penetrate. Roll damage once and apply that damage to each creature hit by the attack. Before making the attack roll, you can expend one use of mythic power to bend the path of the attack up to two times as it strikes targets or objects. Each deflection can alter the line of the attack up to 90 degrees, allowing you to shoot around corners or cover.
And finally, Amazing Initiative reads:
Amazing Initiative (Ex)
At 2nd tier, you gain a bonus on initiative checks equal to your mythic tier. In addition, as a free action on your turn, you can expend one use of mythic power to take an additional standard action during that turn. This additional standard action can't be used to cast a spell. You can't gain an extra action in this way more than once per round.
So, with this combination, would a Pistolero be able to expend a mythic power to use Unstoppable Shot, expend another mythic power to use Amazing Initiative, thus using a third mythic power to use Unstoppable Shot again attacking the same targets and using 1 grit point per target to knock a group of enemies down?
It seems to work, but I'd like a second opinion on it.