Green Nidhoggmon is a deck that easy and cheap to build, easy to play, easy to control the game and easy to win. With the coming of [P-025] Grankuwagamon and [P-032] Palmon, the Nidhoggmon control deck continues to be in Tier-0 in English meta.
Nidhoggmon is comfortable to pair up with other LV6 green digimon, the best candidate in BT4 Japanese card is HerculesKabuterimon from ST4 starter deck, Hercules can rest opponent digimon, give Nidhogmon chance to send them all to bottom of its owner's deck. (Post reference: A Deck Review – Why Green Nidhogg deck is strong).
Now you may say "But now we only can use 1 copy of Hidden Potential, is it still that strong?", I can say with confident that: Yes, it is still strong. Nidhogg is maybe not the main pillar to include 4 copies, but with him in the deck, the opponent needs to worry if he plan to let his digimon unsuspended. Green player normally try to trap his opponent to rest as many their Digimon as possible, then they evolve up to Nidhogmon to send them all to the bottom of its owner deck. Remember that from LV3 to reach LV6 Nidhogmon, it just need 1 memory. It is not as fast as the time we can use up to 4 Hidden Potential in the deck, but green still have great control over the board.
Another Deck Profile for Nidhoggmon in this English BT4 meta is the appearances of promo Palmon at this time. Post to refer to: Soon to be the Tier-1 green deck, this deck profile is introduced in BT5 Japanese meta, but is totally can build and play in English BT4 meta.
Blue Imperial has been a solid contender this format !