SYNERGY/COMBO
KingSukamon (BT11-043) attacks, gains SecAtk for the turn, digivolve into Justimon Blitz Arm (EX2-038) (or Baihumon (BT9-069)) to unsuspend itself, and swing while it still has the SecAtk.
If at any moment you find your Kingsukamon against a higher DP opponent, you want to trigger the inherited of the Sukamon (BT11-040) and you can target your opponent's Sukamon for this first then your own.
SETTING UP FOR THE WIN
WE DON'T CARE ABOUT MAKING THE OPPONENT'S INTO POOP, DO NOT SET UP FOR THAT
Attempt to overun. Turn one should be a chuumon in the breeding area and play a Sukamon flat for 4 memory and pass. Don't chip ahead of time unless you have to. Keep Sukamon's on the field so when you get your KingSukamon (BT11-043) out, it will have more +Security Attack. Having two on the field other than the king makes it swinging for 3 each turn. Then add Justimon Blitz Arm (EX2-038) and you're swinging for 6. You have sukamons on the field with the inherited protection and if king/justimon doesn't finish, they can follow up for the win. You must first attack with a KingSukamon (BT11-043) so it gains the secatk for the turn then digivolve so Justimon is keeping that secatk for the turn. If you have a Chuumon out with other Sukamon's on the field, digivolving from a sukamon will decrease the SecAtk gained from the King attack. If possible, use Suka's Curse (BT14-097) on a chuumon to go straight to KingSukamon (BT11-043).
REASONING BEHIND THE CARD CHOICES
Eggs - Pagumon, duh.
Rookies - I feel like the Chuumons are self explanatory. You can sub in more Chikurimon (ST13-08) depending on the matchup. On the sideboard: Sistermon Blanc is there to discard your sukamon to the trash if you find yourself with too many then you can set up for Kingsukamon's on play and the draw is good too. Junkmon, like a lot of this deck, is just to sit until your combo pieces are ready
Champions - Sukamons are obvious. On the sideboard: I'm personally opting for Mekanorimon. It will slow down your opponent and is a high quality pick from Pridememory boost.
Ultimates - The kings ?
Megas - Justimon CA is absolutely bonkers
Options - parabolic junk and cooties kick are for the chuumon facecheckers to help with the set-up of Justimon
Tamer - Izzy is a good choice
Side deck: Baihumon (BT9-069) and Izzy Izumi & Joe Kido (BT6-090) vs Wide Boards
CARDS ON THE SIDEBOARD
Sistermon Blanc (ST12-12)'s on play discard Sukamons and free draw. Remember, KingSukamon (BT11-043)'s first effect does not trigger unless the requirements are met though we aren't aiming to accomplish that. Sukamons are more valuable on the field than the trash
Deltamon (P-076)'s passive makes it only two memory to digivolve to KingSukamon (BT11-043)
Deltamon (P-076)'s inherited eats the Sukamon if KingSukamon (BT11-043) makes one
Omnimon Zwart (BT5-087) is there as a good finisher and all around really good but I don't believe you need more finishers