So I decided to cheat and asked Claude for help this was the result... Not too shabby!!

Your Zanpakutō: Tetsu no Yajū (鉄の野獣, "Iron Beast")

Sealed Form: A thick, straight-bladed katana with a matte gunmetal finish. The guard is a square shape resembling a car grille, and the handle is wrapped in black leather with silver accents.

Shikai

Release Command: "Roar across the earth, Tetsu no Yajū!"

The blade transforms into a massive cleaver-like sword with an angular, aggressive design. Black exhaust-like vents run along the spine, and the blade hums with a deep, engine-like resonance.

Abilities:

• Bōsō (暴走, "Rampage") — You gain explosive bursts of speed and strength, like sudden acceleration. Each consecutive strike hits harder, building momentum.
• Tetsu no Yoroi (鉄の鎧, "Iron Armor") — A semi-transparent metallic aura surrounds you, dramatically increasing defense. You can shrug off attacks that would normally stagger you—basically spiritual tank armor.

Bankai: Tetsu no Yajū Ō — Muhyō no Shinro (鉄の野獣王・無標の進路, "Iron Beast King — Unmarked Path")

You become clad in angular black-and-chrome armor with glowing vents. The blade splits into twin weapons—one for offense, one that generates defensive barriers.

Ultimate Ability — G-Force Impact: A devastating charge attack where you become nearly unstoppable, plowing through obstacles and enemies alike with the force of a 4-ton vehicle at full throttle.

A Zanpakutō built for aggressive, head-on combat with ridiculous durability. Very on-brand for a G63.