I mainly use hagbane on keri, legend.
This weapon is pure gold against hordes, particularly hyperdense ones, heck its even worth if you get stuck in melee to quickly make some space then draw the bow and shoot infront of you, everything around except yourself gets staggered and dies then or in the next shot.
All for you taking minimal damage in return, which is countered by the kills for health trait.
And with strength potion its the best anti boss weapon i know off, i have consistently managed to take somewhere between 40-50% of a bosses health as it was running towards me by emptying my quiver onto it.
Its damn glorious, even a slayer bardin dropped his beard on the ground in admiration and a “slight” amount of exasperation.
But i do think it could use a slight damage buff against rotblood mobs, these fellows sometimes endure 2 doses of poison and its a tad bit much for normal mobs to do so.
Its fine vs stormvermin and chaos maulers, you just shoot once or twice then melee them, it’s significantly easier once they are poisoned ^^
If encountering too many you just dump 5 shots on em, press F and shoot again if needed.
Usually works as long as things dont go too crazy, like spawn+horde+leech+assassin+gunner or gasrat or some other lineup.