Ninetails (ナインテイルズ) is a secret boss from Mega Man X: Command Mission. He is the strongest enemy in the game and quite possibly one of the most powerful Reploids in the Mega Man X series. He and his clansmen/clones are imprisoned in Central Tower's Special Sealed Area. To confront him the player has to obtain the Central Key by completing the game and face all the other Tails (Onetails, Twotails, Threetails, Fourtails, Fivetails, Sixtails, Seventails and Eighttails).
As all members of the Tails series are based off the same Reploid, they share some basic abilities. However, there are some notable differences between them and how they fight, all of which can be tied back to previous enemies X's party has faced during the command mission. However, all the Tails possess Annihilator Hadoken, which is a hit-all attack reminiscent of the Street Fighter series also produced by Capcom, and Puncture Arrows.
Twotails fights starting in two bodies (like Duckbill Mole) and changes element every turn, complete with Ultra Giga elemental attacks (like Incentas).
Threetails fights starting in three bodies, can use Life Gain 25, and can use status changing attacks: Cryogenics, Cracking, Stungun, Smokebomb and Virus Attack.
Fourtails has stronger attacks than the others, save Ninetails, and alternates between defending according to previous attack type (like Scarface).
Fivetails is relatively weaker than the others, but fight starting in three bodies and can summon/clone other Fivetails by using SOS (the same technique several enemies like Rabbid use to summon alike allies), plus, each Fivetails can use Self-Destruct on one member of the party to hit off tens of thousands of damage (like a Preon S Botos, with power on the scale of a Meltdown's Atomic Fall).
Sixtails has the most LE of all the Tails. If he isn't defeated in ten turns, he will fully recover his health with Life Gain MAX and will boost all his stats. After that, he will use Self-Destruct like the Fivetails. As he has a Tank Part and Figure Coin with him, he must be defeated before he uses Self-Destruct in his 20th turn, or else the player loses them for good and can never complete the Sub-Tank and the Figurine.
Seventails fights starting in two bodies, has regenerative capabilities and gains in strength with every attack done to it (all like Rafflesian's Belladonnas).
Eighttails fights starting in two bodies and can summon/clone other Eighttails with the aforementioned SOS. He fights using Tera and Ultra Giga elemental attacks, Coercion and the two attacks all members of the Tails series possess. In addition, each Eighttails has a 3% chance to drop a LE +1000 or Full Specs +10 Force Metals, and this is the only way to obtain them barring the Force Metal Generator.
Ninetails has the highest stats in all areas, save for LE which Sixtails and surprisingly Fourtails have more of, and the above mentioned moves. He can also utilize the powerful Nine Fragments (砕九), which hits 999 damage 9 times on one party member for a total of 8991 damage.
S-type Attack, hits all party members, damage depends on user's current LE, to higher LE more damage.
C-type Attack, hits one party member, reduces target's WE to 0.
Inflicts 999 damage x 9 to a single target (total 8991pts. of damage). Damages: X Fire takes 499 damage (249 in defense) per hit, and Ultimate Armor takes 499 damage per hit.
Revives fallen party members with 25% of it's LE MAX.
Heavy Fire-elemental damage to a single target.
Heavy Water-elemental damage to a single target.
Heavy Thunder-elemental damage to a single target.
Restores 25% of current LE every turn.
Ninetails has a large array of moves, making him hard to defeat. He can heal himself automatically when it's his turn. His attack "Nine Fragments" refers to his nine tails, which he stabs into his enemies rapidly, causing 8991 points of damage (9*999), which generally kills whoever it was used on. Furthermore, he has the ability to completely drain his enemy's weapon energy with his Puncture Arrows, and the Annihilator Hadoken(滅殺波動拳 Messatsu Hadouken ), a large and devastating energy beam, that sweeps the area and inflicts heavy damage to all of his opponents, and has a 60% chance of being an instant kill, compared to the other clansmen/clones. Because of these attacks it's not a lie when he says, "My strength is unparalleled!"
Instead of normal armaments, the Tails series utilize martial arts and they have the ability to utilize powerful energy attacks and techniques without the need of an outside power source. Upon encountering X's team, each of the Tails simply challenges them to a fight, with the exception of Ninetails himself, who, as aforementioned, claims that his strength is unparalleled.
The game is not clear on whether the other Tails are part of a "real" Reploid series or merely lesser-tailed shadow clones of him similar to the one done by Botos in Chapter 8. Evidence to the latter theory includes the following:
Some of the Tails apparently possess the ability to indefinitely summon/revive/clone themselves.
Most of the other Tails, as pointed above, are basically stronger versions or mixes of past enemies. The only attacks indicating otherwise would be the Annihilator Hadoken and Puncture Arrows, both of which Ninetails is seemingly the only one to have purely mastered.
Each of the Tails actually has the same nine tail spaces visible on their back no matter how many tails are actually there. In fact, the amount of tails is the only difference in all of their appearance.
In either case, he is an immensely powerful Reploid imprisoned by the Resistance in a special sealed section of the Central Tower which requires the Central Key to open, indicating possible allegiance to the Rebellion or some other highly dangerous form of Maverick activity. This is most likely the latter, as he does not mention the Rebellion or have their emblem anywhere on his person. Moreover, he seems to have no grudge with the Hunters, and wishes only to fight them for the challenge of it.
An in-battle detail seems to support the latter statement: He has the ability to actually revive defeated party members, and will occasionally use it. This could be because he doesn't want to end the fight too quickly, or perhaps he is simply a good sportsman.
All of the Tails have the same voice actor.
In addition, they share the same voice actor with Chief R in the Japanese version.