When abyss rising first came out it marked an era of mermails and atlanteans neither archetype is very good by themselves but when combined you got what i believe the best deck of this format. They have many boss monsters now thanks to the cosmo blazer set, but there best would have to be mermail abyssmegalo. He is probably one of the most easy boss monsters i dealt with in yugioh plus his effect that allows him to attack twice is BROKEN. Now another honorable mention in this deck and my personal favorite card in this deck is moulinglacia the elemental lord. When he is successfully summoned u pop 2 cards from the opponents hand, That will prevent them from doing allot of plays. Now like i said the 2 arch types alone wont impact the meta at all because of the fact that they don't have very many good pushes, but what makes em great together is that atlanteans do all the searching and popping, while the mermails have the boss monsters and are able to set the atlanteans effects off. one more card i want to talk about is genex undine, he sets up so many plays, in my opinion he is what makes moulinglacia alive most of the time. Genex undine lets u send a water monster from the deck to the grave to add genex controller to your hand. that card can be a plus 2 while thinning your deck that is amazing. So comment on this and tell me what you think about this deck.