Why bother putting yourself through the troubles of undergoing a typical One-Winged Angel? It's too damn messy, too damn long, too damn late, and it makes you look so damn ugly that it guarantees your death. Hell, your One-Winged Angel might even be clipped as you're performing it, leaving you as an even better target.
However, you can't undergo a One-Winged Angel that completely annihilates your enemies - that's too dull. Such an exaggeration of your badassitude almost always tarnishes your reputation. So, how can you fight your opponents adequately, enough that you're not as likely to lose, but enough that you're not going to win automatically? Find an Empathic Weapon (or make one), and merge with it. You get a boost in power, likely enough to hold your own against your enemies, and your margin of error is about equal to that of the heroes' - it can go either way.
Sub-Trope of One-Winged Angel and Transformation Trinket. Contrast Fusion Dance. Also contrast Natural Weapon (the weapon is already part of your normal anatomy) and Equippable Ally (when something or someone else becomes your weapon).
- In Bleach, the Trope Codifier, this can be found in the Arrancar, an evolved race of Hollows. Unlike the Shinigami, an Arrancar's Zanpakuto is their Hollow form sealed within a weapon, and it isn't sentient. Activating their Zanpakuto is called Resurrección, allowing for a near-complete restoration of their former Hollow selves.
- During the Bakkoto arc. One of the assassins, Jinnai Doko, literally eats parts of his scythe/Bakkoto Retsurai and turns into a monster with the skin made of blades.
- Toward the end of the Bount arc, Yoshino Soma fuses with her Doll Goethe, transforming into a humanoid fire elemental made out of flames and magma. Both entities are still present, but Yoshino is the dominant character in the merger, reflected in their hybrid having a distinctly female figure.
- Ichigo merges with Zangetsu and his inner Hollow to perform Mugetsu.
- The Unison Devices in the Lyrical Nanoha franchise are tiny sentient humanoids who exist specifically to physically merge with their masters and give them enormous power boosts. The only downside is that very few mages can handle Unison.
- Wapol from One Piece can merge himself with a weapon after eating said weapon. This can result in him having cannons in lieu of hands and tongue. He also tries to go over the top by devouring the whole armory of his castle, but Nami stole the key from him in time.
- He used this form once against Dalton in a flashback. And Dalton, who's pretty badass for a supporting character, was completely overwhelmed.
- Secondary character Baby 5 ate the Buki Buki Fruit (Weapon Weapon Fruit), which allows her to turn herself into weapons, including a huge sword and a missile.
- Valon in the Waking the Dragons arc in Yu-Gi-Oh! uses Armor monsters, which do act something like this, given that 1) the Orichalcos power makes them real, and 2) he actually wears them, allowing the player to actually take part in the active destruction of other monsters.
- Joey himself decides to use a similar technique when he duels Valon to gain some armor. He also goes one step further in the duel and becomes his own Monster when he becomes Lord of the Red, gaining a Red-Eyes Black Dragon armor.
- Dartz merges with the Great Leviathan at the end of the season.
- In Claymore, Priscilla absorbed her Made of Indestructium Thunderbolt Iron sword when she first Awakened. She can make parts of her body Nigh Invulnerable thanks to the sword's metal. When she gets serious, she reverts to her original Claymore self and reforms her sword.
- For the first two seasons of Senki Zesshou Symphogear, Hibiki's body is fused with fragments of a Symphogear. Not only do the fragments retain their original function as a Transformation Trinket, the fusion has a number of beneficial side effects including a Healing Factor. However, Hibiki also lacks the Spontaneous Weapon Creation abilities that other Symphogear users possess, has a tendency to go berserk in battle, and overuse of her powers eventually causes the fragments to grow and begin consuming her body. After studying Hibiki, Finé is able to fuse herself with her Relic armor for greater power and in season 2 Dr. Ver is able to infuse his arm with Relic material, granting him a literal Red Right Hand with some of the Relic's abilities.
- Quest for Camelot: Ruber uses a potion that causes this on his army. In the end, he fuses with Excalibur itself and goes completely off the rocker.
- Wreck-It Ralph: Cy-Bugs become what they eat. And they can eat a lot of things. Ralph learns this the hard way when one of them eats his gun, then suddenly sprouts identical guns of its own and starts shooting at him.
- In Power Rangers Operation Overdrive, the Sentinel Knight merges with the sword Exelsior, giving him a physical form once more; he's then able to go from humanoid to sword and back at will. After some adjustments by the team's TV Genius, he also merges with Mack the Red Ranger to give him his Super Mode.
- In Final Fantasy XII, the final battle against Vayne Solidor is broken into three separate battles. In the last battle, he fuses with the rogue Occurian Venat (one of the gods) to form The Undying, which serves as the final boss. In this case, Vayne had kind of been Venat's weapon (against the other gods).
- At the end of Atelier Iris 2, Palaxius pulls this trope when he merges with the Azoth for the final boss fight.
- In Kingdom Hearts I, Ansem, the Seeker of Darkness, merges himself with a giant Heartless ship (Which appears to be the One-Winged Angel form of his Guardian Entity, who more or less is his weapon).
- Used by the Murakumo units in BlazBlue. When inert, their "weapon" is a massive sword that hovers around behind them; when it's time for battle, they merge with it, gaining armor (a little, anyway), Razor Wings and a host of other tricks. The same is true of their prototype, Izayoi.
- Super Robot Wars: After the scrapping of the R-Sword (a Transforming Mecha designed to turn into a sword for the SRX to wield) it was reworked into the "Boxer Frame", a Meta Mecha that can be equipped to the Huckebein Mk-III (and later the Exbein). The Huckebein Boxer's strongest attack, G-Sword Diver, detaches the frame and transforms it back into the shape of a sword, then surfs on top of it to ram into the enemy.