Breeding Blitz (19/07/31)
From Dragon Mania Legends Wiki
Chain Breeding Events are limited-time competitions in which each Trainer participates individually. The objective of these events is to first mate two distinct Dragons, or Dragons with certain Elements, in order to obtain a particular limited Dragon. Once obtained, the Dragon must then be paired with another specific Dragon in an effort to obtain the main objective Dragon.
Dragons already in possession of the Trainer can be used as breeding parents and don't have to be bred again.
As opposed to other forms of limited-time breeding, Dragons made available through Chain Breeding Events are not available to purchase in exchange for Gems, as breeding is the sole method for obtaining them.
The main objective, namely the Cancer Dragon, can be obtained by first breeding for its first parent, the Lava Dragon, and then subsequently breeding it with the second parent, the Mercury Dragon.
The Lava Dragon must be bred for by mating the Fire Dragon with the Earth Dragon. The Mercury Dragon can be bred under normal conditions.