Pride's (Fullmetal Alchemist) shadows can slice through anything.
Longinus Regulus Nemea (Highschool DxD) is a god-slaying battle-ax that at full power could cleave a planet in half.
Longinus Canis Lykaon (Highschool DxD) can create god slaying blades that can slice through anything even space time.
Tessaiga (InuYasha) is a sword that is meant to cut, such that even the Meidō Zangetsuha has evolved to attain the concept of slicing the enemies.
Sukuna's (JUJUTSU KAISEN) cursed technique is divided into two types of slashing attacks. The default slash is Dismantle allowing Sukuna to instantly slash apart his target into countless small cubes. The other, Cleave, can be adjusted with cursed energy to cut down tougher opponents in one powerful slash.
Kurohime's (Magic User Kurohime) Ultimate Sword contains the powers of the four Spirit Kings, which allows her to cut through anything, even the Six High Gods and an entire planet.
Avrute's (Marchen Awakens Romance) ÄRM, Shelakey can cut through any solid material, including other ÄRMs.
Asuma Sarutobi (Naruto) using Flying Swallow to enhance his blade with chakra, increasing its cutting power to tremendous levels.
Naruto Uzumaki's (Naruto) Wind Release: Rasenshuriken releases innumerable wind blades that cut at a cellular level.
Sasuke Uchiha's (Naruto) Sword of Kusanagi: Chidori Katana uses high-frequency lightning to increase the blade's sharpness.
Killer B (Naruto) utilizing electricity on his Supervibrato Lightning Release Swords to create high-frequency cutting power, easily cutting through targets.
Madara Uchiha's Susanoo (Naruto) using its Chakra Blades to project energy slashes...
...and it's also capable of slicing mountains from far away.
Sasuke Uchiha's Susanoo (Naruto) using its swords to slash through meteorites with ease.
Zabuza Momochi (Naruto) can use his Seversword, Kubikiribōchō, with his extreme force to cut through his target.
Ameyuri Ringo (Naruto) wielding the Thunderswords, Kiba, dual blades imbued with electricity, utilizing the high-frequency vibrations to form the sharpest swords amongst the seven.
Jinin Akebino (Naruto) using the Bluntsword, Kabutowari, which uses the hammer to add force to the ax, cutting through all defense.
Samurai (Naruto) can concentrate their chakra into their blades, enhancing and increasing their sharpness.
In his Tenseigan Chakra Mode Toneri Ōtsutsuki (Naruto) grasps one of his Truth-Seeking Balls to create Golden Wheel Reincarnation Explosion, a giant golden sword of pure chakra capable of slicing the moon in half.
Daz Bones/Mr.1's (One Piece) Dice Dice no Mi powers allow him to slice at atomic levels, easily slicing a concrete building to shreds.
Kamakiri (One Piece) using a Burn Blade that ignites compressed gas into a flaming blade, capable of slicing through a giant tree with ease.
Masters of Rokushiki/Six Powers (One Piece) can use Rankyaku/Tempest Kick, a technique capable of sending powerful air blades through their powerful kicks that can slice through concrete walls.
Kin'emon and Brook (One Piece) are masterful swordsmen of their respective rights and styles, with Kin'emon being able to cut flames and iron while Brook is fast to cut.
Trafalgar D. Water Law (One Piece) combines his skill in wielding his Kikoku sword and Ope Ope no Mi powers to project a slash capable of slicing a mountain.
Donquixote Doflamingo's (One Piece) strings are so sharp they can slice through gigantic plants with ease...
...and combining them with his immense strength he can cause a shock wave that slices through his palace's towers with just a kick.
Roronoa Zoro (One Piece) using Santoryu Ogi: Ichidai Sanzen Daisen Sekai (Three Blade Style Secret Skill: Great Three Thousand Great Thousand Worlds) to slice through Pica's giant stone golem.
Charlotte Amande (One Piece) cleanly bisecting Kingbaum with her famous sword, Nodachi Shirauo...
...and able to slice a wall made of strong candy with ease.
Herb (Ranma ½) using Dragon Slicing Flying Blades Wave to create ki blades that can cleave a mountain.
Gein (Rurouni Kenshin) using his diamond-filament steel wires to grasp objects and easily slice through stone.
Monkey King Bambina (Toriko) using his tail to cleanly cut a mountain from its base.
Tsutsuji Amedome (Vanilla Spider) slicing an Elevator alien cleanly in half with his Faucet.
Giiru Ranzu Radisu let's Clear Note (Zatch Bell!) create a giant blade. Made of annihilative energy the blade can cleanly slice through any material.