Board Thread:Questions and Answers/@comment-27868334-20161009044646/@comment-27718903-20161011170650

From what I've heard, Dark types (corrupted ones, excluding The Dark One and Dark Prime Chrono), don't exist in game other than the tournament, so they cannot be obtained. Corrupt Artifact (the one you forgot to add to the list), The Dark One, and Dark Prime Chrono all have other types, therefore they gain the strengths AND WEAKNESSES of those types. You'll notice that, with the exception with Achilles (which I've explained prior), all of the dragons that beat champions are pure types, meaning they are not hybrids. These types have no weakness, and have at least an unbreedable tier (Metal, which falls under the lesser rare tier, isn't as good, but still has a higher chance). Also, the Dark Type, like the Valentine Type, has no effect on breeding outcomes. As far as I know, it doesn't even count towards Diamond.