Fish

Format is not over for worlds' people, but for me it is

Which means it's time for cancerous decks

Today, as the title says, Fish!

First up, decklist:

Monster [29]
3 Stream
3 Tidal
3 Aqua Spirit
3 Coelacanth
3 Mermail Abysspike
3 Mermail Abyssgunde
3 Mermail Abyssteus
2 Mermail Abyssturge
2 Mermail Abysslinde
1 Mermail Abyssmegalo
1 Mermail Abyssdine
1 Fishborg Archer

Spell [9]
3 Gold Sarcophagus
3 D.D.R
1 Storm
1 Reborn
1 Foolish Burial

Trap [5]
3 Call of the Haunted
2 Abyss-Sphere

The point is: Gaios and some good rank 4 xyz monsters

You have a lot of ways to summon the fish: banish (for Gold Sarc/Tidal) then revive with DDR, or Burial/Tidal it to grave then Call, or just tribute summon it thanks to Linde into Dine, or into Pike/Turge discarding Gunde, also there're always Stream, Teus, Fishborg Archer, Tidal, Aqua Spirit and such

Once you have it, bring out all your fish Mermail and start your xyz summoning. Gaios + Dweller/Shock = GG Dragons, Gaios + Shock = GG spellbook. You can even side EEV and No 85 Crazy Box for the Books

Of course Fish + double Dweller = OTK, or Bahamut Shark into Abysstrite/Nightmare Shark/whatever for controlling the board. You have many ways to operate your combos once Coelacanth is on the field, and the extra deck is also up to you

So, what if you cannot get access to the big fish?

Just play like normal Mermail. With Teus/Tidal/Stream, you still have a good chance of making Gaios against Dragons, or some rank 4 against other deck. Prophecy is cancerous though