Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-14749319-20130807065908/@comment-4091815-20130807074856

The twins were members of the same pack.

They could merge but didn't know how to control it until Deucalion came along and taught them how.

They had been treated badly by their pack so once they could form "Voltron Wolf" they took their revenge by killing all the members of the pack and the Alpha who had treated them so cruelly.

Since they killed him while they were merged - the Alpha status fell to both of them.