Stalactunic

Chest equipment — Rare

Your Stalagmages have, "When another Mage enters play under your control, it gets "Diligence - This deals 2 damage to each opposing champion.""

Changes: Stalagmage
Slot: Chest
Rarity: Rare
Set: Scars of War
How obtained: Set 6 Chest Loot

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