Curse of Thirst

I got him down today on difficulty "wisdowm" and get the "Curse of Thirst"

I can confirm, that he dont need to consume the whole anima orb.
In my fight he consumed 3 anima orbs.

I recommand to use pelagos and the boots.
With the boots i'am fast enough to let him only consume 1/2 of the anima orb.
Try to use your shield every time he goes to the middle, so u can make damage an you have not to evade the lines.

good luck

If you do Craven Corinth on Wisdom difficulty you can complete Curse of Thirst, Bare Necessities, and Charmed, I'm Sure all in one go. Please note that it is difficult without equipment but it is 100% doable.

Doing this in TWW, the orb consumption is on a timer, not percentage health.
My strat was choosing Pelagos, pressed the 1 ability once, then ran around until he consumed his orb. Repeated so again until the second consumption, used the 2 ability which killed him, boom achievement unlocked.