Onrane

Onrane is used to open Elite Lootboxes, Ascended Lootboxes, forge vials, ascend Sor Crystals,buy legendary items from the Zol Shop or the Titan Shop and activate new Nodes and Marks. Raids are the best source of Onrane because they drop Onrane Caches which can give 2-10 Onrane and the final boss of the raid can drop an Ultimate Onrane Cache that gives 12-20 Onrane. Elite Lootboxes can also drop Onrane Caches and Ultimate Onrane Caches.
Onrane drops from mid-game and beyond content such as: Crypt of the Illusionist, Catacombs, Alerts and Raids.

Kantos

Kantos is the premium currency for Valor, meaning it can only be obtained through donating. You recieve 1200 kantos per $10 donated. These Kantos can only be used for opening Premium Lootboxes to get Premium Effect Chip which activates a premium effect on 1 character. To see these effects, you must have Particle Master enabled in the experimental options.

Gold

Gold is used to purchase items from the Marketplace, it is the main currency of the server for trading with, it can also be used for buying Backpacks, Character Slots and Vault Chests.
Gold drops from mid-game content and beyond such as: Crypt of the Illusionist, Catacombs, and Raids.

Fame

Fame is only used for making guilds, changing your name and purchasing some items from the nexus.