Nats BWG X

The best BlackWarGreymon X deck I was able to come up with for the nationals metagame. There's a couple of options that I'll go over at the bottom after covering the matchups.

Matchups

Grandis: This is your hardest matchup. They're faster than you, find their pieces before you can win, and don't care about anything you're doing. Grandis needs a second body in front to OTK you so that needs to be your focus. Get a Greymon in the back and then sit on it, hard play an Agumon early (or promote on turn

The best BlackWarGreymon X deck I was able to come up with for the nationals metagame. There's a couple of options that I'll go over at the bottom after covering the matchups.

Matchups

Grandis: This is your hardest matchup. They're faster than you, find their pieces before you can win, and don't care about anything you're doing. Grandis needs a second body in front to OTK you so that needs to be your focus. Get a Greymon in the back and then sit on it, hard play an Agumon early (or promote on turn 2 if you're going first) and use MetalGreymons to delete anything they play. Eventually they'll promote and do 5 checks with a Grandis, then you promote your Greymon, use the cost reduction of Greymon X to go straight to a mega and clear their Grandis, then next turn use Omnimon X to lock down the game. Once you establish an Omnimon X it's very hard for them to come back, but getting there before you die is difficult. If they're slow sometimes you can use X Antibody with the Blitz from Gaiomon to go into an Omnimon X early. Even if you pass 8-10 memory getting the Omni X out is worth it. Sometimes they'll hit Hades Force in sec but it usually doesn't even matter, so you shouldn't try to optimize for that. Matchup is worse than 20/80.

Jesmon: Your second hardest matchup. Usually you want to keep a non-commital board while they set up and have a stack ready to go in the back. Your job is cleanup duty they'll get a combo slower than Grandis but faster than you can win. If you have 2 bodies in play they can't clear both of them and they won't ever really be OTK'ing you. If you can go into BWG X, clear their Jesmon, and clean up a couple Sisters on the turn after they combo you can usually stabilize. Matchup is about 35/65.

Security Control: When played properly this matchup is very favored for you. The plan is to get a Yuuya in play then drip feed your X evolutions to make their options do nothing. With a Yuuya out you go into Grey X then Metal and stop. End your turn with a 10k MetalGrey in play. Next turn Metal X, BT8 BWG, then stop and have a 14k BWG out, and the turn after Gaiomon for 2 more checks trash 1 on unsuspend and still have it around (though not immune to options) on the next turn. Rinse, repeat. Your deck size is important so avoid drawing as much as possible. Hard play promo Agumons and evolve the searchers in the back to minimize draw. You can also use BT8 BWG and Hades Force to target their purple tamers and try to lock them out of the color. Matchup should be about 70/30.

BlackWarGreymon X: One of the most miserable mirror matches in the game, it all comes down to who promotes their stack second. This is why you play the 13th rookie, you want to build a stack in the back and have a secondary stack in the front. Don't commit so hard to the front stack that you have no resources for the back one, just enough to force them to promote. Then you promote, swing over their stack establishing a mega, and you should have enough tempo to make it impossible to lose from there. If they know the matchup they'll be doing the same thing though and it will all come down to who draws better. Matchup 50/50 if you're both good, 60/40 if they don't know the plan.

Rest of the field: Every other relevant deck in the meta depends on establishing a board or stack which is either vulnerable to the dedigivolve on Gaio/MetalGrey or the board control of BWG X. You hard counter Xros Heart, Machinedramon, Mervamon, Mastemon, Galacticmon, UlforceVeedramon, MetalGarurumon X. None of the other decks can really execute a game plan through your disruption and protection. Matchups are somewhere between 70/30 and 80/20 depending on the deck.

Final thoughts

Gaiomon is the best mega, the deck needs to present some amount of aggression otherwise you'll just be too slow and eventually your opponent will assemble some outs. That's why ST Greymon is in the deck too, security attack is very valuable. You could consider going up to 3 Gaiomon and down to 1 BT8 BlackWarGrey but that makes your Security Control matchup a little worse. You could also consider replacing one of the MetalGrey Xs with a BT9 MetalGrey X. The added security attack is good but mainly for the DP increase persisting into your opponent's turn. With Yuuya and BT9 MetalGrey X, your BlackWarGrey goes to 18k which means it crashes with their Grandis, buying you a lot of time. I personally don't like the lower consistency of not protecting against dedigivolve and DP reduction, but it's a call you could make.

You don't bother running Alterous Mode or BT9 Greymon X because the added protection is just not needed and in a lot of cases you'll be skipping the double evolutions anyway, so you won't have that many shots of their effects. You could adjust the Greymon ratio a bit, BT5 Greymon is underrated but it doesn't evolve from BT8 Agumon so it's sometimes a little bit awkward. Aside from that I wouldn't really touch the list in the current meta. Every card has a purpose and the numbers are optimized to give you the best chance possible in your bad matchups without sacrificing your power or consistency in the good matchups.

That said, the deck's weakness to Grandis and the newer Jesmon lists makes it, in my opinion, a bad choice for nationals. Unfortunately the new Jesmon does basically everything BWG X does other than beat Mervamon, but it loses less to Grandis and has a good matchup into BWG X. If you're thinking of bringing BWG X you should just be playing Jesmon instead.