The Ferocious Demigod 1/2 Ocean Drakes don't reward completion.

The Ferocious Demigod 1/2 Ocean Drakes don't reward completion completion when killed as part of the 3 needed. Only Mountain Drakes are counted if the Ocean is the 3rd Drake done to complete mission. I just finished a SR normal draft game where we killed as a team the Ocean Drake and it didn't reward it for the mission.

The stats screen online confirms it was an Ocean Drake will play more to see if it repeats the bug or not.