When you arrive in Bastion, seek out one of the kyrian. Explain that you require an audience with the Archon. Like the Arbiter, she is one of the Eternal Ones who rule over the Shadowlands.
If anyone can guide you to the truth, it is the Archon. Perhaps she will even know a way to end this anima drought.
Once you find the answers you seek, you are welcome to return to Oribos.
Purpose guide your path, mortal.