Butaimaru, (流刃若火, lit. Elemental Perfection) is Ryan's zanpakuto. It has a circular guard that takes the appearence of a dragon and a serpent coiled up, a long dark green sheath and a mid length hilt, which is in the shape of a cobra head. He wears it on his waist. Butaimaru's release command is "Let our wrath be known to all creation!". The spirit of Butaimaru is that of a gigantic deep green serpentine sea creature with a deep echoing voice. Butaimaru is also portrayed to be a blood-thirsty monster, residing in Ryan's inner world, which takes the form a giant misty lake. Ryan is often seen using Butaimaru to instill fear in his opponents.
- Shikai: In its Shikai, Butaimaru extends slightly in length, and gains a crescent-shaped blade attached to its hilt by a long black, metal chain.
- Shikon Kyuushutsu (歯の根救出, Fang of Deliverance): Is the special power of Butaimaru. In Shikai, Shikon Kyuushutsu's blasts are deep sea blue streaks which carry to varying ranges. The power of the attack is capable of carving a large furrow in the ground. When used with a swing at an airborne target, the attack takes the form of a snake-shaped blue blast. However, when used on the ground, it instead rages forward, crushing the ground as it advances.
- Bankai: Koushou Butaimaru (大紅蓮 氷輪丸, Advanced Elemental Perfection) brings Ryan closer to the shape and form of his zanpakuto spirit. He gains a tail made of water, and stands on a cloud of mist made form the release of his Bankai. It gives him access to more water techniques, making him a feared opponent in battle.
- Suishōha (水衝波, Water Shockwave): This technique allows Ryan to make a spiraling vortex of water from the moisture in the air by swinging his blade. The vortex then proceeds to explode from the top in the form of a wave, to which Ryan can control the direction the wave goes.
- Suirō (水牢の術, Water Prison): this ability of Butaimaru creates a wall of water that surrounds a target and then forms a huge contained sphere of water in which to imprison enemies, it is also shown to be immensely powerful. It is thought to be an upgrade of Butaimaru's second shikai power.
- Goshokuzame' (五食鮫, Shark Frenzy): also an upgrade of his shikai powers, Ryan will swing his blade, summoning five water sharks to attack the opponent. They all come in consecutive attacks, starting with one, two, three, four and finally all five start to come into contact.
- Suijinheki (水陣壁, Encampment Wall of Water): This defensive power creates a wall of water that can be up to 360° if necessary with a circular whirl of Ryan's zanpakuto. This wall of water is especially efficient at stopping fire techniques though is unable to defend against elemental fusion and combination techniques.
- Shikon Kyuushutsu (歯の根救出, Fang of Deliverance): is Butaimaru's special ability and technique and also Ryan's signature attack. In Bankai, the attack becomes much more powerful, changing color to a dark green. Unlike the Shikai version, the direction of the green Shikon Kyuushutsu can be controlled with the blade, providing greater range and accuracy. Often, upon contact, it will engulf the foe and create a gigantic explosion. The power of Shikon Kyuushutsu is further increased when Ryan assumes his Vizard form.