Collection is a section within the main navigation in which you can inspect and manage your entire collection of Minions, Spells, Equipment and Artifacts.
You can sort their Minion collections by Rarity, Level and World and can power and level up their Minions, as well as find out more info on each.
Equipment and Artifacts can be filtered by Type, Hero/Minions, Stats and Rarity and sorted by Rank.
You can also choose to Sell their Equipment for Forging Dust individually or in bulk from the Collection menu. By tapping on the Sell button you can select multiple pieces of Equipment to sell, or use the Auto select button to automatically select 10 pieces of Equipment of the lowest power.