What are the Core supply offers in the shop for?

The Core supply offers sell you the currency used to raise your dragons' habits. There are three types of Cores, by rarity:

• Rare Core 🔵 → habits of Rare dragons
• Epic Core 🟣 → Epic dragons
• Legendary Core 🟡 → Legendary dragons

To raise a habit you need one Breedmark (tied to the breed) + one Core (tied to the rarity) — observed cost: around 100 Breedmark + 100 Core per tier, rising after that.

When it's useful: if you're stuck for lack of Cores to finish the ⭐ set habit of a key dragon (the ones that strengthen the Command). What to avoid: buying Cores of a rarity you don't use. Target the Core that matches the dragons you actually play.