This Hunt can be completed any time after you have completed the Draklor Laboratory after going through the Imperial City of Archades. The Bill first becomes available in the Whitecap tavern in the Port of Balfonheim. It is easy to complete at the same time as Hunt 24: The Creature Collector (Goliath – Rank VI).
The petitioner for this Hunt is Popol who can also be found in the Nalbina Fortress. He is sitting in a stall along the Jajim Bazaar.
Deathscythe is located further into the Necrohol of Nabudis than Goliath. Check out the Hunt page for Goliath - Hunt 24: The Creature Collector (Goliath – Rank VI) - for more information on how to reach the Necrohol of Nabudis.
Deathscythe is located in the Cloister of the Highborn area of the Necrohol of Nabudis. Assuming you are close to where Goliath is located or if you just defeated Goliath in the Hall of the Slumbering Might, travel through the room into the Hall of the Ivory Covenant, through that room and into the Cloister of the Highborn.
Very similar to making Dustia appear, you need to reduce one of your character’s health to less than 10% HP and it will materialize close to that party member. You do not have to enter the Cloister of the Highborn with a party member already at less than 10% HP.
You can do this by pressing the 
Button, selecting Attack and then pressing the 
Button to shift from enemy targets to friendly targets. Confirm the action by pressing the Button again and the character will attack themselves one time. Be careful not to accidentally kill yourself and use 
Potions if you have to in order to get the HP percentage correct.
Disable your Gambits to prevent your healer from healing them back up while you are dropping their HP intentionally.
Level: 44
HP: 125,601
Steal: 
Book of Orgain-Mille (55%), Book of Orgain (10%), Capricorn Gem (3%)
The first thing that you should do after Deathscythe appears is heal up the character that you dropped to less than 10% HP. You likely had to disable your healing Gambits so re-enable them.
Deathscythe will cast 
Darkga which will cause Dark-based Magick damage to your party members. It will also cast Doom and Death. Doom will kill your party member after 10 seconds whereas Death is just an instant-death. It will also use a move called Annul which will reduce a party member’s MP down to 0.
Deathscythe will also cast a Paling around itself once it reaches less than 50% of its HP which will temporarily make it immune to physical attacks. The Paling lasts for approximately 2 minutes. Just keep your party alive until it wears off or use Magick attacks to do damage.
This battle tends to be about outlasting Deathscythe while dealing with all of its attacks. MP may become an issue part way through the fight, and it will increase its attack power and defensive power once its HP goes below 20%.
A video of the battle in the Zodiac Age version is included below:
Exit the Necrohol of Nabudis after the fight and return to the Nalbina Fortress. Speak to Popol in the Jajim Bazaar to receive your reward for completing the battle which include 2,800 gil, two 
Hi-Ethers and a Soul of Thamasa.
This is one of the five Hunts required to complete the Jovy side quest.
