PF doesn't have a timer, it lasts until you burst.
It lasts 3 turns.
Originally Posted by Unregistered
Sorry for the noob question, but how is Shingen supposed to be used during burst times? Do you activate Provisional Forest and hope to get your burst back to 100 before the buff ends?
Without her spear, yes, it's rng without help from other hime abilities / summon actives. Otherwise, her spear increases her Abi1's burst gain from 20 to 35, which will guarantee PF within the next 2 turns.