Pools

Pool or tier refers to the order in which groups of arcana and relics will begin to appear in shops. There are 5 pools for each, with pools 1 and 2 being accessible at the beginning of the game. Once you have unlocked enough items total from previous pools, the next pool will begin to appear in shops in both the hub and castle. For example, you will not see Blazing Blitz, a pool 3 arcana, until you have unlocked more than half of the combined arcana in pools 1 and 2.

The Signature arcana sold by Virtuoso Iris for 50 are not bound by pool restrictions and may be any that the player has not yet unlocked.

List of arcana by pool
Note that Chaos arcana are not part of any pool, as they are only unlocked by defeating Master Sura.

List of relics by pool
Note that Cursed and Doctor relics are not part of any pool, as they cannot be unlocked outside of a run.