There are 3 main groups that most decks can be broadly categorized in BT6:
- Reactive group: Security Control, AncientTroy-Nidhogg and Black RoyalKnights Alphamon/Craniamon.
- Mid-range group: 2/3 Musketeers, Titamon and Lilith-Loop
- Rush/big hitters (OTK) group: Gabumon BOF, Jesmon, Qinglong-Hexablau and Agumon BOC.
Based on collected data, the most successful group in competitive meta would be the Rush/big-hitters group, followed by the Reactive group and lastly the Mid-range group. Let's discuss this in a little bit more detail.
In this group, Gabumon-Bond of Friendship has a higher winning consistency. With the power to remove blockers and unsuspending, this deck is sufficiently robust and has a very strong comeback potential: they can easily end the game when you have 3 or less security.
Tied to BOF (or perhaps second) would be the now infamous Jesmon deck. With "Piercing", ridiculously high DP, and multiple attacks, Jesmon's attack can go through almost any Digimon and chips away 2 to 4 securities while at it. On top of that, the 1-cost option card "Precise Tactics" helps Jesmon counter a security control or musketeer deck.
The next one is Agumon Bond of Courage, which behaves more or less like a Rookie Rush deck. It attacks very quickly at the opponent's security using the LV4 promo Greymon (with "Security Attack +1") and ends the game with a Agumon-BOC. Normally this deck also plays some removal option cards to deal with blockers or anything threatening.
Finally, while blue Qinglong and Hexablau do not entirely belong to this group, but due to Qinglongmon's large OTK potential we've decided to include it into the group. But due to board dependencies, Qinglongmon may lack consistency as an aggro deck hence hard journey for this deck to reach tier-1.
The reactive group are generally strong against big hitters, by being able to "react" and potentially turn the tides on the "more straightforward" big hitters. AncientTroymon, in particular, is able to disarm a Gabumon-BOF by suspending it (and another Digimon) right after it's first attack, and similarly against Jesmon, BOC, and Qinglong. You might want to watch a game of AncientTroymon against BOC here.
Security control decks are also still popular (albeit taken over by Musketeers) and remains rather effective against the big hitters, unless if your security fails you.
The black royal knights deck meanwhile, got rather popular lately with some players. Craniamon, being sidelined for 2 metas, can finally shine not only against big hitters (by buffing his DP using Gigadramon and Sistermon Noirs) but also against security control and musketeer decks. His protective effects come in very handy in this BT6 landscape that plays plenty deletion options and effects (see Baohuckmon and BOC) and when buffed beyong 16000 DP, renders BOF useless.
Decks in mid-range typically requires some setup before becoming extremely potent, with the best example being the Lilith-loop deck coming from the previous meta. In BT6, while Lilith-loop is buffed rather significantly by Ginkakumon Promote, it is still unable to compete against the agility of big hitters (often ending the game before the Lilith-loop player has enough cards in hand/trash to setup a loop).
A more prominent example in this category comes in a Musketeer deck, which is perhaps one of the bigger highlights in BT6. By spamming a variety of 7-cost option cards such as Fly Bullet, Trump Sword, and Nail Bone, the Musketeer player will attempt to negotiate and seize control the board while filling up his/her trash with cards that will lower Beelstarmon's play cost. Eventually, Beelstarmon can be played with almost (or entirely) 0-cost, which would be the turning point of the game. Read Kelvin's post for how he navigates a Musketeer deck.
Meanwhile, we feel that Titamon also belongs to this group, despite his aggro properties. Titamon has been rather popular in BT6, having no obvious weaknesses towards other decks. However, it often lacks the OTK aggressiveness of perhaps a Jesmon or Gabumon-BOF deck, and requires the correct digivolution cards and board to maximize it's potential. You may read about it here or watch a video of it up against Jesmon!
While this post attempts to deliver a very broad categorization for the BT6 landscape, it remains naive to embody the subtleties of different decks, builds, and the player's decision making skills into simple categories with obvious advantages and weaknesses. Therefore, please take this post as a generalization of the game and it's meta, and not a point for discourse.