I think there's a mix-up here between Reborn and Rejuvenation. You can get Swablu from Headbutt trees in the Aventurine Woods, off Route 1, which is a fair distance into the game. There are a few Destiny Bond Pokemon that you can get from the mystery egg, but obviously that's not certain. You can get Koffing and Yamask early-ish, and they can learn Destiny Bond, which would be the other option. The alternative is to request any Pokemon with Perish Song or Destiny Bond as an egg move, which I'd be happy to provide for you. Hope this helps