All Slay the Spire 2 characters and how to unlock them

How do you unlock all Slay the Spire 2 characters? It's so easy to think you have a handle on Slay the Spire 2, especially during the early hours. You main the Ironclad, you stock up on attack buffs and big shield cards, and that will see you through - most of the time. You'll soon find that your playstyle will have to change considerably when it comes to the other characters on offer. Before you even consider how to play the other Slay the Spire 2 characters, you'll have to unlock them first, a