One Who Learns The Past - Exterminate the Zealots

First talk to One Who Learns The Past he'll want you to kill some mobs and a miniboss in each group:

1.Kill 5 Anansi Zealots, 5 Anansi Diviners and 1 Anansi Dreamkeeper

2.Kill 5 Anansi Devotees, 5 Anansi Protectors and 1 Anansi Scribe

3. 5 Shy Eremites, 5 Bold Eremites and 1 Calamity Eremite

Upon killing the Ermites: Concentrated Psychic Information will appear in your inventory. Return it to Yutto and you'll be awarded with Flawed Arul Saba Prototype.

4.kill Guardian of Dissent

5.Kill 5 Anansi Orators, 5 Anansi Speakers and 1 Anansi Storyteller

6. You need to loot Brimstone Heart off Brimstone Demon in Burning Marshes, and Scalding Weaver Skin off Scalding Weaver in Sorrow Pass.

7. kill Ansasi Right Hand

8.kill Anansi Left Hand

With that mission complete.

Final reward: Etheral Implant of Berserker Rage