Elixar's Tool Shed

Name: Kurogane: Whisp
Rank: S
Type: Sword
Materials: Carbon Steel Alloy 1090, Fireproof leather. Black Oak, tampered mercury.
Visual Description: Elixar's companion weapon of choice when using just a single blade. The blade's sheath is a sleek, black leather casing, matte finish and has a thin strap that keeps it hung across Elixar's back. The handle protrudes the sheathe. Above the black oak would that makes up the handle, black leather is wrapped around in a crossing pattern that gives it the impression of a katana or blade of that sort before drawn. The hand guard is small and thin to the point its hard to call it a guard, it acts as more of a stopper for the blade and rests just atop the sheathe. Should the blade be drawn, the onlooker would be met with the sight of an obsidian black blade. Styled like a katana with one cutting edge and one flat edge, the blade is actually perfectly straight rather than curved. The blade has also been shined so that it has a slightly paler, shined cutting edge to differentiate it from the rest of the blade. The blade's length comes in at 86 centimeters, and the weight lies closer to the hilt than it does the tip. The blade's material is the hardest steel alloy as of yet, forged by a Takoyaiba blacksmith, it's durability is short of diamond, but not by a long shot. The blade is always kept in as close to pristine condition as possible when Elixar is not out in the field.
Ability:
Major - Speed Boost: A user's active Speed boosts are multiplied by 1.5 using the blade (meaning that boosts caused by Bukijutsu/Kenjutsu are the only boosts multiplied, meaning you can't use this ability on, say, Ninjutsu)
Major - Weight Manipulation: Using the tampered mercury that runs down the centre of the blade, once a user runs chakra down it, the mercury's density and weight changes, causing the blade to suddenly gain/lose weight. The blade's maximum constraints of weight/weightlessness are a meagre 0.04 kg like swinging around a pencil, and a nasty 125kg. At standard, the blade weighs a little over 5 kilo grams. Diminishing weight allows the user to swing faster, with less power whereas a higher weight gives the user the ability to swing harder, with greater difficulty. Switching weights costs 1 set of D rank chakra for up to 10 kg. Weightless "Whisp" grants the user a +15 in speed but drops their strength stat by 20, for every 10 kg, the user's strength stat increases by + 2 and speed diminishes by 2.
Major - Efficiency: Jutsu that go through this blade have their chakra cost dropped by 1 (Capped at D) (Applies only to Kenjutsu)

Cost:
2000 Ryo - Base
3000 Ryo - Speed Boost
3000 Ryo - Efficiency
3000 (Willing to bump to 5000) Ryo - Weight Manipulation

Requirements: A blade of this complexity requires a Kenjutsu 3 at base, Kenjutsu 5 with Weight Manipulation.
The user's effective strength is all that increases when the weight increases, and requires a strength stat of over 75 to wield at max weight normally. For every 20 kg under max weight it requires 5 less strength points to wield it normally.