Cephidian

"Cephidian" is an archetype of Fusion Monsters introduced in Morning Star. It is almost entirely composed of WATER Sea Serpent-Type monsters, with the one exception being the trump card of the archetype, "Cephidian Dreadcaller". They all share an effect that changes one (or more, in Dreadcaller's case) opponent's monster to face-down Defense Position.

Strategy
The main goal of a "Cephidian" Deck would be to take advantage of the Spell Cards of the archetype to make Fusion Summoning easier and combo the monsters' effects to get even more powerful monsters on the field.