Now, for the combo of the deck, the cards you always want to have or find are Garurumon X, Weregarurumon promo, Weregarurumon X, and X Antibody (BT9-109) option card. These are the core combo pieces of the deck.
For the OTK startegy, you want to build safely on your hatching area a Weregarurumon promo line with any garurumon (most prefarably the promo one) and Garurumon X for protection. If you are lucky enough to have a Gabumon X as well, you might want to digivolve it on the breeding area on top of your Gabumon. But if you need to dig for more cards, you can play it instead.
To be able to OTK, you will either need 1 of the following cards on play, Nokia Shiramine (BT5-092), Blue Memory Boost, Cool Guy or your opponent gave you 4 memory. This will ensure that you will be able to digivolve to MetalGarurumon X and be able to attack for game since it is a 4 cost to evolve.
On your turn, you will raise Weregarurumon from hatching area. You will attack directly once, then restand/unsuspend (if you have garurumon promo, you will draw 1 card as well). If the security check is bigger, activate Garurumon X protection from battle. Then, play the X Antibody card and place it under Weregarurumon, attack directly again triggering the effect of X Antibody to digivolve to Weregarurumon X from your hand for free and be able to restand and return level 4 or lower Digimon.
Since you now have the inherited effect of Weregarurumon Promo active (as long as you have 8 or more cards in hand), it will now do 2 checks instead. If successful, you will now be able to attack directly again for 2 checks and trigger the effect of X Antibody to digivolve to MetalGarurumon X and restand again. You can attack for game here if you are still the turn player. Else, you will have a blocker and Digimon removed from your opponents side. As much as possible, you will want to always go OTK route. You can do this by setting up necessary cards or by attacking the security while building up the core pieces on the hatching area.