"Nubatama" (ぬばたま) is a clan from the nation of Dragon Empire. They are one of the Dragon Empire's espionage corps, with a focus on gathering intelligence. This clan has no known leader, although it does seem to be led by the "Congo" faction.
Nubatama is a control based clan that focuses on cutting down the opponent's hand. Nubatama generally lacks in aggresive potential, so instead they weaken the opponent's hand to make it harder for the opponent to defend against their attacks. The main way they do this is by bouncing an opponent's rear-guard back to their hand then forcing the opponent to discard a card, which weakens their field and forces them to either lose potential Shields to keep the bounced card or lose that important rear-guard. They can also directly discard a card from the opponent's hand, and in some cases limit how many cards the opponent can have in their hand at the end of the turn, forcing them to discard the rest. In addition to this, Nubatama also uses multiple cards with "When placed" abilities that can be reused by bouncing them and calling them again.
The Magatsu series follow a Hit-and-Run strategy by bouncing their own rear guards to the hand, which leaves less cards on the field for the opponent to target and allows them to superior call from the hand during the Battle Phase to do more attacks, giving them more aggresion that the rest of the clan normally would.
VG-V-BT07 introduced the "Evil Decoy Token" which can intercept from the back row allowing the player to conserve hand advantage, they can also be retired to pay for the Cost of skills or have an opponent's attack redirected to them, wasting that attack.
Nubatama has ProtectImaginary Gift, which allows them to stall the opponent while they continue to reduce the opponent's hand.