Normally people use "Blue" to play Rookie Rush because it gives many <Draw+1> (Read one blue hybrid rookie rush review here). Seeing a red rookie rush mixes with some green digimons is kind of new for me, especially this deck is totally extremely rookies-play style. There is no LV5, LV6 or LV7 at all, it uses the lowest level which is LV3 and LV4 only, and still strong enough to win tournament. Check out the deck here.
There is 3 types of LV3 Agumon are used in this deck, makes it total 12 cards to serve the purpose of <Securitycheck+1> for [P-010]Greymon.
The cheapest cost [BT3-007] Agumon, with only 2 costs to play directly from LV3. The other two, [P-009] and [ST1-03] Agumon should be used to digivolve from digitama. Once it reaches [P-010]Greymon, this digimon gains <Securitycheck+1> check.
LV3 and LV4 digimons, It has a bunch
All cheap 2-cost LV3 digimons are used in this deck, red [BT1-009] Monodramon and [ST1-02] Biyomon, and green [BT3-044]Aruraumon. The LV3 red [BT2-010] Biyomon is put in to gain +1 memory "when destroyed". The LV4 [BT1-019] Darktyrannomon, which only 1 cost for digivolve but providing 6000DP, that can deal with blocker since normal blockers are 6000DP only.
Free play from Security check Digimon
This deck is using upto 8 cards (2 digimon types) for security digimon that can play at end of the battle, gives 16% of chances that it can be in security pile.
BT3 Union Impact gives these new type of digimon called security digimon. For red, it is [BT3-011] Greymon and for green, it is [BT3-049] Flymon. But even if they are not happened to be in security pile, it can be used as normal LV4 digimon to digivolve from LV3 with 2 costs.
Deal with Blocker or Rookie Rush Sweeping Digimon
Rookie Rush is easy to play, but it is fragile. This deck includes 2 option card types (total 8 cards in deck) to deal with opponent blocker or powerful digimons.
[ST1-16] Gaia Force can deal with any type of digimon in the battle (rest or active), the [BT3-104] Positron Laser : up to 2 of opponent digimon cant attack or block until the end of opponent next turn. The Positron Laser is used when you think you can win next turn and Gaia Force is used for emergency since it is expensive to play (8 costs). This deck also use a 1 cost option card [BT1-108] Horn Buster, 1 digimon gets +3000DP until the end of your turn, but I think it is great if it is hit from Security pile, can rest one of opponent digimon.
Weakness: The enemy of Rookie Rush, [BT2-018] Volcanicdramon, "When Played: Destroyed all the opponent's digimon with 400DP or less"