Katanas are elegant, yet deadly weapons in Elden Ring: Nightreign. Most Katanas come with innate Bleed buildup, which makes them ideal for builds that focus on inflicting Blood Loss upon enemies. They provide decent damage output with great moveset, especially when powerstanced. However, unlike heavier weapons, they deal less poise damage and don't stagger larger enemies easily with hits.
NightreignKatanas - Nightreign Wiki

Dragonscale Blade
Katana • Lvl Required 7
Weapon Skill: Ice Lightning Sword
Call down a bolt of ice lightning into the blade and bring it down upon a foe. The ice lightning effect will persist for a while.
A weapon made by sharpening a Gravel Stone scale, thought to be the source of ancient dragon immortality, into an unclouded blade. Alas, the Dragonkin Soldiers never attained immortality, and perished as decrepit, pale imitations of their skyborn kin.

Executor's Blade
Katana • Lvl Required 1
Weapon Skill: Unsheathe
Skill of swordsmen from the Land of Reeds. Sheathe blade, holding it at the hip in a composed stance. Follow up with a normal or strong attack to perform a swift slash attack.
A single-edged katana with a long, sharp curved blade. A unique weapon wielded by the samurai from the Land of Reeds. The Executor found the sword abondoned in the aftermath of a battle, and has wieldedit ever since. Stained with gold and rusted blood.

Hand Of Malenia
Katana • Lvl Required 10
Weapon Skill: Waterfowl Dance
Perform a series of one-footed leaps in the manner of a waterfowl to unleash a swift yet graceful slashing combo. Repeated inputs allow for up to two follow-up attacks.
Unique Weapon Passive: Power of the Undefeated
Blade built into Malenia's prosthetic arm. Through consecration it is resistant to rot. Malenia's war prosthesis symbolized her victories. Some claim to have seen wings when the weapon was raised aloft; wings of fierce determination that have never known defeat.

Meteoric Ore Blade
Katana • Lvl Required 3
Weapon Skill: Gravitas
Skill originating from the Alabaster Lords, who had skin of stone. Thrust the armament into the ground to create a gravity well. In addition to dealing damage, this attack pulls enemies in.
Katana forged from meteoric ore to dispatch lifeforms born of falling stars. Deals magic damage. The blade is weighty, known to deliver slashes of such ferocity that the impact is said to resemble the crash of a falling meteor.

Moonveil
Katana • Lvl Required 7
Weapon Skill: Transient Moonlight
Sheathe blade, holding it at the hip in a composed stance. Follow up with either a normal or a strong attack to draw the blade at great speed for an instant slash attack. Both attacks fire off a wave of light.
Katana forged of glintstone. Masterpiece of a Sellian swordsmith. Light enwreathes the blade when sheathed, explaining its Moonveil moniker.

Nagakiba
Katana • Lvl Required 3
Weapon Skill: Unsheathe
Skill of swordsmen from the Land of Reeds. Sheathe blade, holding it at the hip in a composed stance. Follow up with a normal or strong attack to perform a swift slash attack.
Katana with a ferociously long blade. Signature weapon of Yura, hunter of Bloody Fingers. Reminiscent of a reinforced spear, its imposing length can be put to good use with powerful thrusting attacks.

Rivers Of Blood
Katana • Lvl Required 7
Weapon Skill: Corpse Piler
Forms a blade of cursed blood for repeated, interweaving successive attacks. Follow up with an additional input for further successive attacks.
Weapon of Okina, swordsman from the Land of Reeds. A cursed weapon that has felled countless men. When Mohg, the Lord of Blood, first felt Okina's sword, and madness, upon his flesh, he had a proposal, to offer Okina the life of a demon, whose thirst would never go unsated.

Serpentbone Blade
Katana • Lvl Required 3
Weapon Skill: Double Slash
Skills of superior swordsmen. Perform a crossing slash attack from a low stance. Repeated inputs allow for up to two follow-up attacks.
Sinister katana modeled after a serpent bone. The densely packed row of spines that jut away from the cutting edge are coated in a lethal poison.

Uchigatana
Katana • Lvl Required 1
Weapon Skill: Unsheathe
Skill of swordsmen from the Land of Reeds. Sheathe blade, holding it at the hip in a composed stance. Follow up with a normal or strong attack to perform a swift slash attack.
A katana with a long single-edged curved blade. A unique weapon wielded by the samurai from the Land of Reeds. The blade, with its undulating design, boasts extraordinary sharpness, and its slash attacks cause blood loss.