Here it is, the culmination of all my experience playing Dangers, Kaijus, and board-breaking decks in general.
For your consideration, I present to you;
Danger Kaijus; The Rank 8 Specialists
So, let's review; obviously this deck will not be *as* good against a backrow-oriented deck on the first round. That said, if back-row is all they have, between Bigfoot, Thunderbird, and your extra deck (which contains my old friend Heliopolis! :D blow up ALL the things!), you can take out a decent chunk of their resistance before you go neck-deep into your main play.
What is the main play, you ask? Why, XYZ summoning into a Draglubion OTK of course. >:)
I personally enjoy going into a Rank 4 support card like Daigusto Emeral or Dugares to help your resource management and pad the amount of Ranks on the board, then do the thing, because this guarantees a Number 100 with at least 13,000 attack which can OTK over any of your Kaijus. If you have enough for an extra Rank 8 first, you could also go into some hand trap insurance, like Photon Lord or Dingirsu (for destruction effects, specifically). And from there, the strategy is more or less as it always has been;
Go second, break whatever board they have over your knee, preferably with a sickening snap, and run them over with the lorgest of lads.
Seriously, while I haven't been able to test it in person, I've been playing a lot of Dueling Nexus and the deck's performed admirably, especially for a deck that relies so heavily on luck and the gods of RNG. There's a heap of draw, a fair bit of recycling, and a great extra deck toolbox to handle a wide variety of situations.
The side deck is based almost entirely on specific match-ups. The back-row hate is for Sky Strikers and other back-row oriented decks, the Jinzos are for freaking Elditch. Dark Ruler No More is in there for the same reason the C Tachyon is; just seems like a generally reliable choice when attempting to shut down a board that's beyond even our ability to outright blow the heck up, or if there are shenanigans afoot with monsters who have specific immunities. There Can Be Only One still pulls it's weight admirably after all this time, and the Virus... Ok, so look. Full Force Virus is basically a filler until I do more testing. That could be any Virus. Or any other two cards. But Full Force felt like a nice one to hit combo starters, monster-based hand traps, and other kinds of strategies out of the hand before they become a problem.
So that's it. That's the entire deck laid bare before us. Hope you like it. :)