Mystical Shawl

Chest equipment — Rare

Your Arcane Dreamcatchers instead have, "Prophecy - When this enters play, exhaust all opposing troops. The next troop in your deck gets +1/+1 and cost - for each troop exhausted this way."

Changes: Arcane Dreamcatcher
Slot: Chest
Rarity: Rare
Set: PvE Promos (Armies of Myth era)
How obtained: Set 3 Chest Loot

What it does is the game's own text; how it was obtained is from the owner's records.