The Scythe is a unique, powerful melee weapon that is swung in front, above, and below Ikk, dealing 2 damage to enemies in its path.
The Scythe does not use traditional ammo. Every time you use the weapon, you will lose a round of ammo only if your strike does not hit an enemy. Your ammo is kept at or refreshed to your maximum if you do hit an enemy. This means you can use the weapon in rather quick succession as long as you continue to hit enemies.
Touching a floor/wall or hitting/jumping on an enemy will refill your ammo.
You begin with 3 ammo, which can be upgraded to 5 and 8 by reaching Sally on full health.
The weapon is obtained via the merchant's shop found before facing a boss. It will appear as a purchasable item by paying the merchant glyphs to re-roll the available items until you completely run out of glyphs. Since you've now run out of glyphs, you must shoot 5 mushrooms on the ceiling in a single combo to obtain the one glyph necessary to purchase the weapon.
The Scythe with the Shark Fin Edit
Using the Shark Fin backpack while equipped with the Scythe sends Ikk off into a several second insane barrage attack, during which he can travel quickly through the air, destroy enemies rapidly, and is virtually invincible. It's pretty dope.