During Chapter 22 (Solo), your up against a bunch of Daein Mercenaries who have taken up refuge in a Church, and geuss what? They're using Priests as Roadblocks to stop u from advancing. Now this can be tricky, but its easy. Firstly, there are three Bishops (Staffs and light magic) going up the middle hall way, when following this path, unequip any long ranged weapons and keep your spellcasters out. Use shove to beat the preists and bishops out of your way and kill the boss as fast as posible (theres no turn limit, its just to be safe). If u succeed in not killing any Preists or Bishops, at the end of the mission they'll give you the Ashera Staff. Its a "S" level staff that heals all allied units to their full health and recovers status alinments.