How did I craft:
Tier (2)3 Unique + Arcane Crystal -> Invalid Tier (3)4 Unique
Examples:
Fauztin's Visage (Field Plate) turns into Shroud Royal (Full Plate Mail)
Body armor that gives All resistance and Vitality (base Studded Leather, but no the one from guide) turns into The War Cloak (Quilted Armor)