Item
Mystic's Crest
Unique
Effect
The holder counts as a 
Mystic during combat.
Where it drops
No drop source recorded in the game files.
Other Unique items
Questions people ask
What does Mystic's Crest give in Guildrun?
The holder counts as a Mystic during combat.
How many items can a hero hold?
Three at ranks C, B and A, and four at rank S. Specializations and relics can push that higher, up to a hard cap of six. The Executive alone adds two.
Can I equip the same item twice?
Yes. Doubling up is legal and is used in real builds. The Rush Duelists build on the tier list runs two Vanguard's Bracelets on Rip.