Wallbreaker Wave is an imperial discovery in Final Fantasy XV that neutralizes the Lucian royalty's magic and even enfeebles Astrals. Seeking to invade Insomnia protected by the magical Wall upheld by King Regis, Niflheim Empire had begun developing technology to overcome it. The "wave" they had discovered produced exceptional results in real-world conditions, inhibiting the Kingsglaive's warping and spellcasting abilities—powers that operate on the same principle as the Wall. Niflheim discovered that the wave can neutralize not only the Wall, but all magical phenomena exhibited by Lucian royalty. Based on the data acquired from the encounter with Shiva, Niflheim also expected an enfeebling effect on the Astrals.
It is unknown if Niflheim used the wave during their encounters with Titan and Leviathan, but when Loqi Tummelt and his magitek infantry invade Lestallum during the Assassin's Festival, they deploy the Wallbreaker Wave to cut Prince Noctis from the power of kings, believing this renders him harmless. He can still warp, and Noctis prevails even without his magic, and Cindy Aurum helps by disabling the generator that projects the Wave, granting Noctis back his powers.
Noctis later infiltrates the imperial capital of Gralea, and finds his powers fading, unable to summon his weapons or use magic without the Ring of the Lucii. When he makes his way to Zegnautus Keep, he discovers a large red generator in the wall near the throne room, and gets an ominous feeling from it. He turns off the device with a control panel in the throne room and regains his ability to use magic.
Though the wave is said to disable the royalty's magic, it doesn't disable the powers of the Ring of the Lucii. When Noctis finds the Sword of the Father from the keep he is able to use it and warp with it even before turning off the apparatus that seals his powers. Ardyn also seems immune to its effects, and enables Gladiolus and Ignis to summon their weapons.
- In the Omen short film, Noctis loses his ability to use magic, similar to what happens when his powers are sealed in Final Fantasy XV. This part of the film was patched into the main game as a dream Noctis has when he stays in Lestallum.
- When the Wallbreaker Wave is in effect during Assassin's Festival, the air ripples in blue static effect.