- "A sword that cuts through anything. Passed down from abroad a long time ago."
- —Description, Final Fantasy Crystal Chronicles: Ring of Fates.
Zantetsuken (斬鉄剣, Iron-Cutting Sword?) is a recurring weapon in the Final Fantasy series. It usually appears as a curved scimitar, either with a blue blade or a blue aura. It is the trademark weapon of Odin, wielded by him in all his appearances, and shares its name with his trademark attack, Zantetsuken. However, it can also be used by other characters, and can sometimes be equipped by the party.
- "May randomly dispatch an enemy in one hit."
The Zantetsuken is obtained after defeating the Blue Dragon in the Ancient Castle, or by betting the Lightbringer in the Colosseum. It has an attack power of 208, has a 25% chance of slicing the target (works even on the undead), and enables the Bushido and Runic command. It can be equipped by Terra, Edgar, Cyan, and Celes, and is the only non-katana weapon that Cyan can equip. In the SNES and PSX releases, the weapon was called the Scimitar, and it is affected by the Capture Glitch.
Gilgamesh obtains Zantetsuken from Odin in the battle against Seifer, and will from then on randomly appear during battles and use one of his four swords, one of them being Zantetsuken. It instantly defeats most enemies but misses against bosses, Tonberries and Cactuars.
Gilgamesh wields a replica of the Zantetsuken, with a skull marking above the hilt to signify that, like all his weapons, it is nothing more than a fake.
Odin, Lightning's Eidolon, wields the Zantetsuken during the Eidolon battle with him, and when he is summoned. Once he enters Gestalt mode, Lightning fights using these blades. The blade is composed of two parts of equal size, which can be attached and detached at will. While Odin fights with these blades combined, Lightning separates them during Gestalt mode.
Gilgamesh wields a different Zantetsuken from Lightning and Odin's in the downloadable battle against him. It inflicts Wound damage. Final Fantasy XIII-2 Ultimania Omega reveals that Gilgamesh's Zantetsuken is from the Dissidia universe and is implied to have belonged to a manikin of Chaos, as it is said to be discarded by Chaos as his nails grew, but appears to be made of crystal and is "just a husk".
The Zantetsu is as a weapon for Clavats with 80 power and The description reads "A sword that cuts through anything. Passed down from abroad a long time ago."
- "A sword that cuts through anything. An ancient heirloom from a distant country."
The Zantetsu is a Sword that can be used by all races. It provides 50 attack at level 1 and 130 attack at level 30, gives +5 to Stun, and has one empty slot and one slot occupied by the Samurai Lore ability. It can be obtained by finding the scroll at Ruins 2 on Normal difficulty, and then creating it for 270 gil by using up three Steel, a Black Silver, and an Adaman Tusk. When turned into a jewel, a level 3-9 Zantetsu makes a Bushidore, level 10-19 makes a Holy Stone 3, and level 20-30 makes a Will Stone 6.
Lightning's weapon transforms into the Final Fantasy XIII version of the Zantetsuken when she executes an HP attack, and she wields the swords while using her EX Burst. Her level 100 exclusive weapon is also named Zantetsuken. It provides +68 attack, +10% defense, and a Riposte effect, and can be traded for in the shop for an Omega Weapon, Survival Knife, five Flash's Hopes, and 182,800 gil.
Gilgamesh uses a different version of the Zantetsuken as one of his eight random weapons when attacking. It bears the Iai Strike ability when attacking, and thus has a chance of inflicting Bravery Break on the opponent if his attack connects.