Danger Abhyss Go second

First of all, you NEVER want to go first. Your endboard will most likely suck. This deck has way more power going second. You might have seen versions with viruses and other weird lair-related stuff, it makes the deck inconsistent while having an okay-ish endboard. Sure, going first IF you can assemble all 3 of the Abhyss boss monsters, you have a decent board, but nothing crazy and you need to open some disgustingly good hand to assemble it (which this deck could as well). The payoff for going first is really low, but you can consider siding some viruses if you know your opponents is going to make you go first.

The idea is to injure the opponents board with strong equalizers before spamming your field with reptiles and accessing your Xyz 8 toolbox. Curse and Aleth make it easy with snake rain so you can end game quickly with Numeron Dragon. If you can't otk that turn, then setup your Aron and Amunesia to disrupt your opponent's follow up.

Lair of darkness is insane in this deck and so is Darkest Diabolos. You can tribute your opponent's monster to summon yours from the graveyard , which bypasses almost every kind of protection. It's one of the easier ways to get rid of problematic cards. Even Arima is nice, not only because it searches Lair, but it's effect is actually useful : you can search Nihil, Nessie, Jackalope or Diabolos depending on what you need.

Lamia, Echidna and Hydra are nice little engine that clears boards and gives you cards to work with. It doesn't interact well with targeting protection though. Be careful with Echidna, as her search effect prevents you from going into your Rank 8.

Dangers are here for "consistency" and they open up Xyz play. Its weird to speak about consistency with danger!s but that's what they actually do here, kind of how they did in Thunder dragon back in the days. There is just no better equivalent to "extenders that load the graveyard and cycle through the deck" and you need all of that. Tsuchinoko is searchable with King of the Feral Imp or Echidna, which is actually very relevant because one more monster can be crucial to tribute for your Abhyss graveyard summons.

If you don't open your equalizers, try baiting as much negates as you can, you will see that you can go through much.

The side deck is just good going second cards, but you can put whatever you like as long as you can break boards. Careful with the barrier statue of the wind, as you will need the wind insect kaiju to out it as Gameciel don't work. Be sure to pack Backrow hate as that kind of deck can become akward to deal with. As I said before, viruses can also be considered in the side for going first.

Weakness to droll&lockbird,  Skullmeister, Ghost Belle and backrow heavy decks.

Some edit after more playtest : added Number 23 Lancelot and AA-Zeus, super good if you can't otk.

Let me know in the comments if you would make any changes or if you disagree with my point of view. Hell you can comment if you like the deck as well ! I truly believe this is the good route ! Enjoy !