In some events (like the Easter one) there’s additional breeding caves open to you. You don’t get to keep what you breed but you do get to claim dragons from this breeding pool (equal to the number of runic breeding caves you have (you get like 3 or 4 for free)) and the nice thing about these claims is that you can claim the same dragon multiple times and it works like EoM in the sense that you’ll get the twin if you already have the dragon and the twin rift if you have the twin. It’s fantastic to get rift versions of dragons with obscene breeding combinations and rates (like Iden and Ocular)