This is the premier martial art created by the greatest hero of Greece, Hercules. While it originally started out as a technique he created to use with his bow and arrows to simultaneously exterminate all one hundred heads of the Lernaean Hydra, an immortal nine-headed serpent that would grow back no matter how many times it was cut down, it succeeded. Upon slaying the Hydra at the end of a lengthy battle, Heracles devised this combat technique and expanded it to be usable with any weapon. It transformed from a combat technique into "Heracles Style: Shooting the Hundred Heads," an all-purpose Noble Phantasm capable of adapting and changing its appearance depending on the target and the circumstances of its use. Just as with the Hydra, which had the circumstance of "resurrecting no matter how many times it is killed," this martial art adapted the trait "exterminates no matter how many times his opponent resurrects."
Upon gaining this, you have a basic level of mastery with every armament in existence, regardless of whether it is delivered with a bow, large sword, shield, spear, axe, or possibly even unarmed. The greatest aspect of this technique isn't its ability to adapt, but its ability to draw out the maximum power of any weapon it's used with, whether that be a bow, sword, shield, or spear. This makes them the greatest of their types in the moment the style is used with them. This is what puts this art on par with Noble Phantasms.
At complete mastery, you can display power from Anti-Unit to Anti-Army, and even up to fortress sieging, all depending on the target. Anti-Unit Nine Lives Blade Works with a series of slashes and the Anti-Phantasm Beast skill that discharges nine dragon-like homing lasers at the enemy. It's described as "a high-speed attack consisting of nine consecutive strikes, as swift as if the attacks are overlapping." Similarly, just like with the Hydra, there are one hundred simultaneous attacks that cancel out regeneration.