Archer/Hunter Help Can't Beat Dr. Legendary For Some Reason?

(105 Archer)
I can easily solo every boss in LI except for Dr. Legendary, he just heals faster than I do damage.

Note: This is the best build I can afford atm, and It's from a few years ago, as I haven't really played this much for 3+ years.

Clearsight Spectacles
Aquarius
Vaward
Scorpio
Prism x2
Diamond Hydro Bracelet/Necklace
Torrential Tide

I'm not interested in spending 10+le on new items, I'm just wondering why I can solo Cybel and every other boss with a few potions yet I can't solo Dr. Legendary.

 

This build is absolutely horrendous in today's standards, and the reason you can solo any other boss is because doctor legendary has a very high hpr, as you've mentioned, and you simply don't have enough dps.
You might wanna check out Cluster, Orange Lily, Gale's force or Hive infused bow builds, as those are frequently used in endgame and they do more than enough dps to solo Dr Legendary.

 

What has changed on that build

- Rainbow slap is nerfed many times
actually there's no point of using prism in here
- Torrential Tide is nerfed

https://forums.wynncraft.com/thread...machine-tips-on-building-explanations.265923/
maybe this would be helpful