In both the DC Animated Universe and the comics it inspired, Batman Beyond showcases the most technologically advanced Batman we've ever seen. And while his patented black and red suit is one of the most recognizable and powerful suits in Batman's considerable wardrobe, it's still dwarfed in raw power by a special prototype built by Bruce Wayne in the twilight of his career.
The X7 prototype was seldomly used, but the times it's been pulled out of the vault had grand implications on the Bat-Family. The X7's most notable appearance plays out through Batman Beyond #6-11, by Dan Jurgens, Bernard Chang and Marcelo Maiolo.
In the world of Batman Beyond, Bruce Wayne kept on as Batman well into his golden years, and it eventually caught up to him. Once he realized Batman was on the verge of failing for good, he designed a suit with one goal in mind: to succeed at ANY cost. He did this with a ruthlessly intelligent artificial intelligence that could override the user's pain receptors and allow them to tank incomprehensible amounts of punishment.
In Bruce's last case, he used the X7 suit to defeat a cult of venom-using thugs who call themselves the Banes. Even after the Banes demolish Bruce by breaking his back in multiple places and numerous other bones, the suit takes over and eliminates the entire gang with extreme measures. Bruce locked the suit away in his vault meant for no Batman to ever use it again because it broke Bruce and put the final nail in his Batman career.
Terry McGinnis became Bruce's replacement several years after the original Dark Knight hung up the cape and cowl. Bruce never told Terry about the X7 Prototype and was placed in a medically induced coma by Terminal before he could properly warn Terry of the technology. Terry found the suit in the vault and threw it on, oblivious to its potentially harmful effects.
The suit consists of burning red energy coursing through a black bodysuit with a Bat-Symbol and eyes glow with a devilish red. The suit also has extra weaponry in the form of wing-blades and claws that grow from its gauntlets. The suit also has more advanced delivery systems for his most used gadgets like Batarangs and explosive pellets. It's most deadly weapon is a set of Batarangs that whirl like helicopter blades and cut enemies to shreds.
Terry gets a real taste of the X7's power after he defeats an entire platoon of League of Shadows assassins, single handily. Once he defeats the platoon of assassins, he quickly heads to the League of Shadows HQ to face off against the Demon, who he later learns is Damian Wayne, Bruce's biological son. During the battle, Terry is able to easily overpower Damian's super-strong bat-dragon Goliath.
Little does Terry know, Damian also rocked the X7 Prototype during his short stint as Batman. Damian's experience with the X7 Prototype also dealt with a League of Shadows threat. Once the R'as Al Ghul embraced technology and retrofitted the entire League of Shadows with advanced weapons like automatic rifles and armored assault vehicles, Damian set out to prove his father wrong by stopping R'as while and the X7 Prototype's power and influence. "Damian went after the league with a ferocity that sent chills up my spine," Bruce remembers. After Damian wiped out the League's army in no more than four hours, he just disappeared and left the tattered X7 suit for Bruce to find.
The next time Damian appeared, he was wearing the Demon's hood, facing down Terry with little more than a sword. Having worn the suit himself, he quickly takes advantage of the suit's weaknesses. Damian not only counters every gadget and move Terry throws at him, but he also batters Terry without much issue. The suit's AI is ravaged in battle and tries to overwrite Terry's control to kill Damian. With its last burst of energy, he squares up a killing blow, but Terry fights back for control, spares Damian and stops an entire fleet of cruise missiles headed towards Neo-Gotham.
This was the last time the x7 Prototype suit was used. Bruce always thought the suit's AI influence was too strong for users to resist. After the "Rise of the Demon" arc, it's clear that both Damian and Terry used the suit in ways that Bruce never could and showed the technology's true potential.