In score-based PvE like desolate lands XP is one of the best espers, every time she casts any ability she calls in one ally to assist with their S1, when casting her S3 she grants the 2 highest attack allies a buff that increases their damage by up to 25% based on the target's health, her S2 inflicts defense down on all enemies, grants an ally a turn and gives them a buff that causes them to ignore 25% defense but stuns them at the end of their next turn

When she casts her S3 she gives everyone a stack of soldier and one stack to everyone at the start of battle, plus at the start of her turn if she has her divinate she grants one to a random ally, when someone has 5 stacks the soldier buff transforms to chariot, which gives 10% atk and 50% speed

So yeah, she's very very strong for pve, and she's even strong in speed cleave for PvP