Pathfinder 2e Spell: Mystic Armour

You ward yourself with shimmering magical energy, gaining a +1 item bonus to AC and a maximum Dexterity modifier of +5. While wearing mystic armor, you use your unarmored proficiency to calculate your AC.

Heightened (4th) You gain a +1 item bonus to saving throws.
Heightened (6th) The item bonus to AC increases to +2, and you gain a +1 item bonus to saving throws.
Heightened (8th) The item bonus to AC increases to +2, and you gain a +2 item bonus to saving throws.
Heightened (10th) The item bonus to AC increases to +3, and you gain a +3 item bonus to saving throws.