Butterfly's Sting (Combat)Source Inner Sea Gods pg. 208 (Amazon), Faiths of Purity pg. 24 (Amazon)
You can forgo a critical hit in order to pass it on to an ally.
Prerequisites: Combat Expertise, worshiper of Desna.
Benefit: When you confirm a critical hit against a creature, you can choose to forgo the effect of the critical hit and grant a critical hit to the next ally who hits that creature with a melee attack before the start of your next turn. Your attack only deals normal damage, and the next ally to hit the target automatically confirms the attack as a critical hit.Source Weapon Master's Handbook pg. 24 (Amazon)
When you confirm a critical hit, you can spend 10 stamina points to use Butterfly’s Sting without forgoing your own critical hit.