The Xros of a Super Ultimate and 5 different Mega Level Digimon certainly does prove one's authority whenever it's used in battle, SuperMechadramon is designed as Commander Kiryu's main Digimon as an artificially create Digimon create by humans. It's power is said to be able to take on Shoutmon X7 Superior Mode, all Seven Demon Lords, Brondramon, Cobaldramon, and Jadedramon all at once. It's power is above Super Ultimate due to the combination of Digimon used to form it's body. It is based on and is a tribute to the Megazords of the Power Rangers series. It's height is around 400 feet tall, making it one of the largest Digimon known. Due to the specific way both it's in-game model is and how it DigiXroses with it's component Digimon, it is completely immune to the effects of the limiting effects of the DigiQuartz, and due to that, can become SuperMechadramon easily.
However, despite this supposed Legendary power it has and is capable of, there is an EXTREME weakspot that leaves any combination of Mechadramon in a vulnerable spot. It's status as a Dramon Digimon should be obvious enough to opponents such as WarGreymon and VictoryGreymon, both of whom are armed with Anti-Dramon weaponry. Not only do both of their respective weapons deal incredible damage to SuperMechadramon, but specifically, if you strike the DigiCore of KiryuMechadramon (The central base of each combination), then the entire combination practically implodes on itself and destroys all of the composite Digimon forming the body. Even some non Anti-Dramon weaponry was capable of dismantling it to scrapheap, as Imperialdramon Paladin Mode's Omni Sword is fully capable of completely impaling SuperMechadramon. To say anything of how Omnimon would handle in a fight against SuperMechadramon would be too easy to describe, as Omnimon would simply demolish whatever armor stood in it's way and go in for the kill. With this in mind, SuperMechadramon is best used to counter Digimon that are solely Dramon Digimon types, rather than anything that isn't lest it risks it's own ability to stay alive...
However, while its power is indeed strong, many say that SuperMechadramon itself is fueled by having an ego larger than even Etemon's family, to the point a mysterious force is what allows SuperMechadramon to win fights in the first place. This was eventually proven that SuperMechadramon was not as powerful as it had appeared when ZeedMillenniummon had the honor of facing SuperMechadramon and had all but erased him in seconds flat, thus proving that SuperMechadramon's "power" was fueled by an immense ego over anything else.
Appearances
Digimon World: Bronze and Cobalt Versions
It is obtained after having obtained KiryuMechadramon, which is needed to obtain the other 5 Mechadramon required to form SuperMechadramon. KiryuMechadramon is obtained after having becoming Legend Tamer and having beaten The Grand One as a gift from Commander Kiryu. Commander Kiryu can then be faced in the Super Tournament questline, where you can battle SuperMechadramon in it's full power. SuperMechaDramon is a Size 10 Digimon, though KiryuMechadramon, which is the same height, is a Size 5 Digimon.
Digimon: Bursting Cries
It is Commander Kiryu's main partner Digimon. It rarely has any need to appear, but whenever the time is right he brings out SuperMechadramon upon those who cause the most trouble, easily beating every opponent and proving his authority as commander.
Prior to the 3 part arc at the beginning of the 3rd major arc, SuperMechadramon is only briefly seen in tiny glimpses, or as it's separate component Digimon instead, leaving the fact Commander Kiryu having such a powerful Digimon completely in the dark, even though he's had it since the very beginning of the season. In the final part of the 3 part arc involving Duo being revealed as a Draglimon, Duo goes on an uncontrollable rampage and KO's Brondramon, Cobaldramon, AND Jadedramon all at once, while not even taking a scratch from any of them as well. She then reverts nearly every other character's partner Digimon down to fresh. She even manages to completely block Euoplodramon's signature move, which is capable of causing mass destruction in it's wake, as well as KOing the other Crest Guardians as well. Fracktamon appears briefly to try and attempt to stop her, but is easily outmatched when Duo not only hits it's only vulnerable spot, but does so while causing it to explode to pieces. Even when the Starter Trio is degenerated to Fresh, they each use digivolution discs to force themselves to become Trinitimon only to easily be KO'd as well. When Kiryu finally had decided it was time to reveal his SuperMechadramon, he sends it out against Duo, and the titanic Digimon at first appears too powerful for Duo, but even the imposing Omni+ Level Digimon, the first Omni Level Digimon to appear in Bursting Cries, is not enough to stop Duo's rampage. It is actually Marcus and ShineGreymon Burst Mode teaming up with SuperMechadramon that snaps Duo out of her rage, but it doesn't last when she just changes to Draglimon again only to end up passing out after giving Commander Kiryu a huge thrashing. Counting it's offscreen appearances up to this point, this is the only time SuperMechadramon actually lost on it's own at this point in the season.
SuperMechadramon's next major appearance is when The Grand One hijacks it with three of his own Mechadramon, all to form UltraMechadramon, and uses it to blast a supersized D-Reaper clone to death with it's cannons, after the D-Reaper had already been rendered helpless by Gaiamon bombarding it from clear orbit. The final appearance of SuperMechadramon is when it is used against ZeroDragoramon, and with even more Mechadramons in Duo's disposal, as the entire Digimon set now belongs to Duo, she combines them all to form UltimateMechadramon Superior Mode and destroys ZeroDragoramon with it.
Digimon Re: Story
The original SuperMechadramon is referenced with a lot of negativity towards it by older Digimon. These Digimon were veterans of those who had to fight this guy, as all of them claimed that, while SuperMechadramon was indeed strong, his own ego was far too much for his own good. After Shoutmon X7 Superior Mode lost to him in a cheap, one-sided battle, SuperMechadramon was baited into fighting ZeedMillenniummon, and thus it resulted in his destruction for good... until the scrap metal would arrive in another dimension and eventually be rebuilt and salvaged into armor for GranLocomon...
SuperMechadramon Fission Mode
SuperMechadramon Fission Mode is the reason why every Mechadramon except TitaniumMechadramon was killed off at the finale of Bursting Cries, due to the fact at some point in the 12-17 years they were in development, Stellerdramon and Photondramon were designed as Mechadramon, and even have the slots necessary for them to replace the Red and Black Mechadramons in the combination, increasing SuperMechadramon's power to deadly heights. While it is incompatible with the Weapon Mechadramon TurquoiseMechadramon and the to be revealed VioletMechadramon, they are still able to combine with TitaniumMechadramon, which is the combination some say should never be possible due to how broken UltraMechadramon is already. Some could say the very user who controls this mighty Mecha would rule the entire universe with an iron fist, but even The Grand One does not decide to keep hold of this formation for one reason; The Fission Combo is dangerously unstable, and the fact that both Solar Deities are both larger and heavier than the Mechadramon they replace in the combination, make SuperMechadramon very top heavy in weight, and even TitaniumMechadramon struggles to carry the weight of the combo, although it's function is not hindered regardless. If Dragoramon was smart enough to outright avoid the Fission Dragon duo, what The Grand One was playing at in terms of their creation is still left in the dark, as their full power extent is unknown.
Digimon World: Aftermath
Due to the other Mechadramon's destruction in the anime version, this combo is exclusive to the game, in which SuperMechadramon nor any of it's other components were not only never destroyed, but multiples are capable of being created based on players trading between each other. SuperMechadramon, and all Mechadramons except Titanium, are exclusive to B/C/J, which means that in-order for this fusion to be created the proper Mechadramons must be traded over from B/C/J. Due to the sudden power boost compared to simply using TitaniumMechadramon, Stellerdramon and Photondramon cannot be immediately Xrossed with the Mechadramons right away. First two special key items must be obtained, both of which require Red and Black Mechadramon, which will unlock a challenge mode that pits the player's Digimon against Brondramon, Cobaldramon, and Jadedramon all at once, and only after winning can the Overdrive Key, which is necessary for the stability of the combination to be maintained, is unlocked, which you are then free to combine the two Fission Dragons with SuperMechadramon. If Yellow, Blue, and Pink Mechadramon are not used in the combination, then the Digimon's level is Omni+, which is the same as normal SuperMechadramon.