One of the many currency types you can collect in is Abyss Stones, which you can only get from a single source. Abyss Stones are spent in various ways, from unlocking new characters to providing important stat upgrades.
This resource may be the rarest you can get during a run, making it extremely valuable to farm whenever you enter the Overgrowth.
Abyss Stones are oftentimes used in tandem with Cores in . Cores can be found in Stashes around the Overgrowth, with some being locked behind containers guarded by a barrier in the world.
You need a Key to unlock these barriers, but you can also farm four Core Shards to automatically create a full Core while you explore different biomes.
There are two functions for Abyss Stones that are more specific than other currencies in . Unlike Material or Bright Blood, Abyss Stones are farmed in much smaller numbers, with only a few usually held onto your character for a time.