So Cyberdark Impact and Elemental Hero Stratos aren't okay for the game, but this is allowed? Permanent minus 1600 to 2400 attack on everything your opponent has, not to mention this is how procrastinate decks win. Okay Konami.
I don't think anyone in the history of ever has said Cyberdark Impact is a card that would be too strong for Duel Links. (Realistically, even if we had Impact and Dragon at the BEGINNING OF DUEL LINKS, the only problem would be the base Cyberdarks.)