Dragon Force (竜の力 Doragon Fōsu) is an advanced Dragon Slayer ability.
When a Dragon Slayer enters Dragon Force, they effectively turn into a humanoid Dragon, gaining reptilian scales and traits, such as further elongated, and sharper, canines and scale-like patterns on their skin. According to Zero, Dragon Force is the final, most powerful state a Dragon Slayer can attain; granting them power comparable to that which a real Dragon possesses: the power to utterly destroy everything.
Dragon Force greatly increases the damage done by standard Dragon Slayer spells, and grants the user access to more advanced, powerful attacks. It also drastically enhances the user's physical prowess, speed, and considerably boosts their Magic Power, which becomes visible, taking the appearance of a Dragon. When exuded at its fullest, said Magic Power takes on a violent corporeality, likely as a result of the immense amount of Magic Power employed. When Natsu Dragneel entered this state through the use of Jellal Fernandes' Flame of Rebuke, his flames gained the ability to burn off offending Magic, even that of Zero's ultimate attack Genesis Zero. The effects gained when entering Dragon Force can be temporarily stopped by separating the Dragon Slayer Magic from its user with the use of a Separation Enchantment.
- For First Generation Dragon Slayers, those who have been taught their Magic by a real Dragon, certain conditions must be met in order to enter Dragon Force: the only one known so far would be to eat substances with powerful magical properties, preferably those somehow related to the element they can control and consume; while other, unrelated substances can be eaten as well, these have been described as being similar to "poison" for the user, causing heavy after effects, such as pain on activation and extreme exhaustion after use. Natsu Dragneel, Gajeel Redfox and Wendy Marvell, all three of the First Generation Dragon Slayers, have entered Dragon Force, initially requiring an external catalyst to do so. This occurred on five occasions: Natsu's first was the consumption of Etherion, followed by Jellal Fernandes' Flame of Rebuke and then from Ignia's flames while Wendy through eating air with an extremely high Ethernano concentration, and Gajeel did so through consuming Magical Barrier Particles released by Bloodman. Later, Natsu was the first First Generation Dragon Slayer to enter the state without an outside stimulus; Wendy did so as well after one year of training. Interestingly, she lacked any sort of draconian features normally associated with Dragon Force, however, with successive uses, these features reappeared.
- Second Generation Dragon Slayers, those who have been implanted with a Dragon Lacrima, are capable of normally entering Dragon Force; the most notable features are scales that run across the arms and possibly bulking through the transformation.
- Third Generation Dragon Slayers, those who have not only been taught by a Dragon but also have Dragon Lacrima implanted into their body, are capable of freely entering Dragon Force. However, the appearance of their Dragon Force is slightly different from the previous generations, for instead of actual scales, a scale-like design appears on their face and body. When used by a Shadow Dragon Slayer, this Dragon Force can become exponentially more powerful if the user is possessed by their shadow, also causing the scale-like marks to cover their body even more than before. This Dragon Force has also been shown to be further empowered by consuming another Dragon Slayer's element, entering a dual mode on top of it and thus amplifying the user's powers even more.
- Fifth Generation Dragon Slayers, those who have devoured Dragon flesh or cannibalism of other Dragon Slayers, are capable of freely entering Dragon Force. However, it has been stated that the use of Dragon Force is forbidden as it differs from the previous generations since it hastens the drawback of using Dragon Slayer Magic, turning the user into an actual Dragon with them becoming berserk from the process. When activating their Dragon Force, their body and muscles becomes bigger and their overall appearance becomes more feral.