So, the idea behind this deck is pretty simple. I wanted a 3 pronged deck - Prong 1 is hand traps - I've fit 16 in. Prong 2 is Necrovalley. Prong 3 is the Adventurer engine, which puts up a negate + Dracoback and puts pressure on the board. That's basically it, let's take advantage of Necrovalley being a pushed floodgate with lots of support, let's put up Gryphon Rider as often as possible, and lets see 2 HT as often as possible to really try and stop people's turns.
Into the card by card. I wanted to run HT in force, so most of the best generic ones are here. 3 Maxx "C", 3 Ash, 3 Veiler, 3 Imperm, 2 Gamma with a Driver, and 2 Ghost Ogre. Some of these are good tuners that can help you put pressure on the board, but our real goal is just to not lost turn 1. I also wanted a full playset of Cosmic Cyclone.
After that, you want to see exactly 1 copy of Necrovalley, and you can run 5, so I'm running 5. Not much to say, this shuts down a lot of starters, extenders, and combo lines. We're just trying to floodgate people out with this card. It does conflict with Foolish Burial and Dracoback, so you can't mitigate the downside of Adventure as often on turn 2, and you need to know how to sequence Necrovalley, but even most idiots should be able to figure it out T1. It hurts almost every other deck more than ours anyways.
After that, you want all 5 of your Adventurer engine starters, but you also want 2 Adventure and 2 Gryphon Rider. Seeing these together puts up Grypon Rider, but mostly we're just running these so we aren't out of gas vs a single Cosmic or Ghost Ogre.
That left 5 slots. I felt like Called By was just too good to pass up in the deck, the card is very strong and close to an autoinclude. I also felt like raw card advantage would be pretty important for a stally stunny deck like this, and it really needs to see the Adventurer engine sooner rather than later. It also doesn't use the Extra Deck, so Pot of Extravagence makes sense.
The extra deck are mostly cards to make with your tuners, as well as cards to send vs Dogmatika Maximus. You should dip into this very often, but Baronne/Chengying is great to make with an unused Ash and Gryphon, and Omega/Draco Berserker is good to make with Gamma.