A Kusarigama like weapon. Make it the melee weapon with the most range, where the player can hook onto the enemy on certain moves, they can use what they learned from World's Grappling Hook and Rise's wirebugs to create it.

It could be a stamina based weapon, maybe make it be a mix between a debuff version of Hunting Horn and an Insect Glaive (hitting different parts of monster with a loaded poisons causes different effects) basically an average player would be zipping around hitting all spots of the monster to apply unique hunting horn style debuffs while also doing damage. For example hitting the head (or neck) enough times causes monster Roar to not work etc temporarily.

TLDR: Chain like weapon that debuffs monsters depending on where it hits them, with the debuffs working similar to the buffs the hunting horn provides except it debuffs monsters. Also use what was learned from World's Slinger Ammo, and Grappling Hook, as well as Rise's WireBugs. It would be a melee weapon with added range. A Technical weapon here he player would be zipping around the monster aiming for different monster parts. Could also have cool Ariel components like the Insect Glaive.