Few swords warrant a theme song
Name: The Zushakon
The Zushakon is like every other sword ever... before passing the hooked hilt, which features a right-handed and closed partial basket fashioned to keep chunks and liquids (which might otherwise causing slipping or poor grip) from splattering on the hands and fingers. It is only slightly heavy due to its composition, requiring two hands for better accuracy, but it can be used generally with only one hand. Replacing the traditional blade is a rounded plate to which a segmented chain with small razor teeth at sharp angles is fixed, the entirety of which being 99.2% pure unalloyed titanium.
The Zushakon is forever ravenous.
As a result of its source of energy, one can't truly use its power without an affinity for Eneton. When Eneton chakra is applied, the energy jerks a specialized chain into a repetitive two stroke motion, which will rake and flay anything from bone to concrete. The chain continues to kick back and forth until it leaves the user's hand or chakra is no longer supplied.
Unreasonably difficult to wield precisely without basic understanding of Weaponry, an unversed wielder such as Sathoggua is incapable of performing anything but the sloppiest and most destructive of swipes with it. The intense vibration and sawing motion makes it extremely unpredictable and dangerous to anyone proximate to the wielder, including the wielder himself! However, this intrinsic danger also provides a superior advantage; parrying, when managed with Zushakon, will very likely result in forcefully kicking a weapon from anything short of an expert grip.
There is no more definitive balls-to-the-walls type weapon. The deafening clack of the chain strokes are perfect for giving away your location, and there probably is no louder sword in the world... probably. As with the many drawbacks of equipping a customized chainsaw, this can also be a blessing in disguise. Zushakon's metallic leviathan of a bellow is also an unsurpassed distraction and pollution of sound, quite efficiently masking the telltale sounds of allies. In all, Zushakon's transparent hazards and weaknesses are sometimes double edged assets both to one person and a team, ensuring that using it is at least viable (if irrational).
Initially, the teeth will shred and carve deeply, but they are less likely to cause horrendous disfigurement when they are fresh. The teeth tend to wear out quickly through any prolonged physical contact, after which they are corrupted into instruments of ripping and tearing, rendering flesh and bone into crude strings and flying globs. Anything malleable which so much as kisses the underside of the chain (between the chain and the fixed plate) will be crushed and shattered, while more durable things such as weapons could be bent or flung.
Don't stick your fingers in there.