Icejade

Deck is made for trad format, side deck has meta relevant cards/handtraps that can help the deck out. If swapping to make a legal deck that uses handtraps, swap PoG, surface, & the 2 water hazards.

Main goal of the deck is to slam down Cosmocroix early to lock up opponent's monster effects. Agel can draw either Cradel card, depending on what you need, but if you have Cosmocroix or Icejade Cradel in hand, add the field, if you have Inion Cradel or Terraforming in hand, add Icejade Cradel instead.

Sea serpent cards in the deck are the basis for all the synchro monsters, with Diva being able to pull one of 2 ways to synchro to 7 or going into Halq to which pulls another tuner (usually Minstrel) and any one of 4 tuner synchros. Clear Wing helps protect Cosmocroix, Dragite negates backrow, Brionac is used to setup Moulinglacia as it allows you to choose how many water monsters go in your grave & provides minimum 1 target for Moulinglacia to discard.

XYZ's are much more difficult to get out as most require Acty to summon as it's the only level 4 in the Main Deck. Should you be able to summon them, Number 37  can work in tandem with Cosmocroix to make your opponents lose 4600 attack for 2 turns. Silent Honor ARK helps remove big Extra Deck monsters while bypassing destruction protections, Bahamut Shark & Toadally Awesome combo sets up a spell/trap negation, Leviair helps pull back icejades that have banished themselves and allows for some recursion in the deck, and Abyss Dweller is mainly for if you no longer have Cosmocroix & your opponent is trying to use grave shenanigans.

Called by  & minstrel provide protection against Ash Blossom which is one of the worst handtraps for this deck as you need to pull a cards from deck w/ agel unless you  open with a perfect hand. Side deck provides additional protections in the way of instant fusion/restrict or dragged down/dimension shifter. Infinite impermanence is among the best cards in the side deck to switch out for as it stacks w/ Cosmocroix to prevent monster effects even on the turn they're summoned, letting you stun your opponent. Nibiru & DPE packages are both for removing big threats, Nibiru keeps things from ever hitting the board, while DPE stops effects that don't proc on summon & has flexibility to destroy back row as well.