Essence is a currency that can be used to upgrade items, convert items into their dungeon variants, or be spent at Essence Shops. There are many different types of Essence, each obtained through different methods.
Essence can be used to upgrade items and convert them into Dungeon Items in a process known as "dungeonizing". Each Star Upgrade grants a +2% stat boost: Dungeon Items grant a +10% stat boost per Star Upgrade while in the Catacombs.
Dungeon Items can have a maximum of 5 Star Upgrades; items upgraded with Crimson Essence can have a maximum of 15 Star Upgrades.