The Catalyst Weapons are a powerful set of six weapons found during the Planetary Fonic Arte events in Tales of the Abyss. Each weapon possesses a hidden, untapped power that allows them to draw strength from defeated enemies, similar to the Devil's Arms, the Fell Arms in Tales of Vesperia, and the Shadow Somas in Tales of Hearts R. The full strength of these weapons is unlocked only after the group defeats the replica Gelda Nebilim at Nebilim's Crag.
The Catalyst Weapons consist of the following:
- Nebilim is Luke fon Fabre's Catalyst Weapon. He obtains the weapon from the "Blade Rex" in the Meggiora Highlands.
- Lost Celesti is Guy Cecil's Catalyst Weapon. He obtains the weapon from Emperor Peony IX in Grand Chokmah.
- Blood Pain is Jade Curtiss's Catalyst Weapon. He obtains the weapon in exchange for finding a missing rappig in St. Binah.
- Holy Quelquatl is Natalia Luzu Kimlasca-Lanvaldear's Catalyst Weapon. She obtains the weapon from a chest in Baticul's Abandoned Factory.
- Heart of Chaos is Anise Tatlin's Catalyst Weapon. She obtains the weapon from Florian, who discovered the weapon while sifting through Ion's belongings. It previously belonged to Fon Master Evenos.
- Unicorn Horn is Tear Grants's Catalyst Weapon. She obtains the weapon at Yulia Jue's grave in Eldrant.