Nubatama is, or well to put it more aptly, was a clan that focused on forcing your Opponent to discard cards from their hand when their attacks hit successfully. They had an initial print of four unique Units in Booster Set 1: Descent of the King of Knights with the archetype name of “Stealth X” X being a creature type such as “Beast” or “Dragon” (their individual names were “Hagakure”, “Dreadmaster”, “Chigasumi” and “Voidmaster”). However there have been no more cards printed with the “Nubatama” clan since. It is speculated that they were discontinued, most likely due to their skills being far too powerful for this game. The introduction of Murakumo, who use a similar aesthetic to Nubatama and are the deck now used by Kyou Yagahi (who previously piloted Nubatama) in the Manga further suggested that Nubatama will never be granted any more support. The aim of the following article is to detail out why Nubatama aren't actually all that frightening with full support, provided of course certain caveats in design are enforced.
“Stealth Dragon, Dreadmaster” is the card that makes every player wary about granting Nubatama a fully functional deck, even if the additional Units are vanilla (without skills or their only skills are common power up abilities) at best. I can understand why they are so cautious but I honestly believe it's a misguided concern. Dreadmaster has the ability to discard a card from the Opponent's hand for a cost of a single counterblast provided the Nubatama he boosted landed a successful hit against any unit while the attacking player has less cards in his hand than his Opponent. I won't deny this skill isn't great, it is but what people fail to realize is that we already have a very similar card, in a different clan that is gaining support, that actually has the potential to do even MORE than Dreadmaster.
“Midnight Bunny” of Pale Moon is the card I'm referencing. Midnight Bunny allows the player to swap itself with a Unit in the soul (who comes out standing, ready to attack) for a single counterblast when the Pale Moon unit it boosted lands a hit against any Unit. I will concede it's a tad more difficult to have a viable attack Unit in the soul than it is to have less cards than your Opponent in hand but even then it's not too far of a stretch.
Both Midnight Bunny and Stealth Dragon, Dreadmaster are practically useless in the early game because they have no counterblast available to pay for their costs and during late-game the Opponent won't be in a position to allow them to hit because if they can't guard, they have, sans a freak heal trigger, lost the fight already. Both units shine during the mid-game, where they have counterblast available while their Opponent isn't currently in the eventual “guard everything” late game (both units do excellent behind the Vanguard for this reason).
As I mentioned above, Midnight Bunny has the potential to do just as much as if not more than Stealth Dragon, Dreadmaster. There are two main scenarios to consider,
The first scenario is the same for either card; Both units boost units with the same power and get guarded for an advantage of one card.
The second scenario is slightly different; Same as above except both units are not guarded and all attacks are aimed at the Vanguard, in the case of Dreadmaster we have gained an advantage of one card, from his skill, and one point of damage. In the case of Midnight Bunny, we have called another viable attacker so we have gained an advantage of one damage along with either one card, if the new unit was guarded, OR an additional point of damage if the new unit wasn't guarded.
To simplify that, Dreadmaster can do no more than +1 Damage, +1 Card but Midnight Bunny can reach +1 Damage, +1 Card or take it further to +2 Damage (I shouldn't need to explain why, strictly speaking, life is much more valuable than cards in Vanguard). There is a third scenario that involves attacking a rearguard but all you need to know is Midnight Bunny comes out on top again. So Midnight Bunny, a card in a clan that is still gaining quite a bit of support can, under the right (and relatively easy to fulfill conditions) do more than the card that everyone is quite afraid of “Stealth Dragon, Dreadmaster”.
It should be also worth mentioning, that outside of Heal Triggers, Dreadmaster can only successfully use his ability up to five times a game and that is while not allowing for counterblast anywhere else in the deck. It sounds like quite a bit but it really isn't considering a few things, such as the fact that those five cards will be discard over the course of a game yet each players from mid-game and onwards draws three cards a turn through the combination of the normal draw and the twin drive. It's quite a miniscule amount when you consider it in light of that. At worst it emphasizes that the defending Player should guard the Vanguard during the mid-game more (which is, strictly speaking, a bad idea outside of circumstances like these) but ever since the introduction of units in Booster Set 4: Eclipse of Illusionary Shadows, that are considered acceptable by the majority, such as “Stern Blaukluger”, “Amber Dragon, Eclipse” “Evil Armor General, Giraffa” that has become quite a common practice. Again I'd like to emphasize the point that while Dreadmaster is quite a good unit, it doesn't do nearly as much damage as some would like you to believe.
“Stealth Dragon, Voidmaster” is another Unit in Nubatama that shares a similar skill to “Stealth Dragon, Dreadmaster”. Again, for the price of a single counterblast when Voidmaster hits any Unit while the attacking player has less cards in their hand than their opponent, they can have their opponent discard a card from their hand. The kicker here is, and a clever one at that, is that Voidmaster is a Grade 3 with a mere 9000 power. Playing any Grade 3 with a power of 9000 opens players to abuse from attacking units who can now easily form columns that force 15000 or more guard each for basically no effort at all. It's pretty annoying to go around and do all that work to take a single card out of your Opponent's hand, only to have two taken out of yours per attack leaving you, the Nubatama player, in a worse spot than that of your opponent.
This leads me into the main design caveat if Nubatama were to become a fully functional deck If we consider the fact that 20000-21000 columns have become a common event since the release of Booster Set 6, during the late game, just as many, if not more, cards are going to be easily forced out of Nubatama's hand as they were pushing out during the mid-game. This would lead me to conclude that Nubatama would be acceptable provided, like Kagero, they have weak base power Vanguards (e.g. 10000 power) and a hard time to reach 20000 and or 21000 columns without dedicating themselves to Vanilla play or inflicting a penalty on the user.
It should also be noted that because Nubatama are essentially a control deck, that there shouldn't exist any cards that create instant advantage, such as Blaster Blade, but rather focus more on simplification and essentially be focused on card quality advantage rather than card quantity advantage. A good example of this would be a Persona Blast that costs a single counterblast to discard the specific grade 3 unit from to force your Opponent to discard. It's a one for one in terms of straight advantage, except you had to pay a counterblast to activate it but your Opponent probably had to discard something with a shield value of 5000 more often than not.
In conclusion, as mentioned above Nubatama has the capacity to exist as a fully functional deck if aforementioned caveats (and probably additional ones that currently elude me) are taken into consideration along with the above reasoning to as why Stealth Dragon, Dreadmaster isn't all that much we fear him to be.