pf2e.fyi
From Pathfinder War of Immortals, which isn't enabled.

Mark of the Sage

FEAT 16

Usage imbued into a worn ikon


Your ikon gains a pin, stripe, or similar marking showing you as a master of your craft. The imbued ikon gains the following ability.

Transcendence—A Challenge for Heroes (concentrate, mental, spirit, transcendence)

You declare an enemy within 60 feet to be a heroic test. For 1 minute, that enemy deals an additional 10 spirit damage to you with each successful Strike or spell it targets you with.

Effect: A Challenge for Heroes (Enemy)

Whenever that enemy deals spirit damage to you, each ally who has the enemy in melee reach can attempt a Reactive Strike against it, even if the ally doesn't normally have that reaction. If an ally successfully slays the enemy with a Reactive Strike due to this effect, that ally immediately gains temporary Hit Points equal to your level, which persist for 1 minute.

Effect: A Challenge for Heroes (Ally)

Pathfinder War of ImmortalsORC