For the first time, speak with Tiffy Cashien about the Temple Knight base and he'll take you there. You can either start the miniquest, or leave it. There's a possibility RS Gold. Callon, the Temple Knight Commander. Callon will inform you and ask for your help in investigating the Mother Mallum's activities.
You seem to be extremely alert. Tell me, have any new leads been identified? Actually I don't think you have any knowledge about Kennith? Who? He's a young man from Witchaven. Now, you'll describe what happened during Kennith’s concerns. I will immediately call for an investigation. You're an Proselyte and the most close person to the situation, therefore I'll give you a fee. I had another mission though. I'm looking for you to deliver an actual sea slug.
Sounds tough. Would it be possible to find you a different aquatic mind control animal? If you can locate one, we might be able to have an inspection, even if they're not in any way related. To find the "other mind control creature" visit Braindeath Island via Pirate Pete, and fish some sluglings and a Karamthalu as you did during the quest. Take it to Callon for analysis, and you will be sent to ask questions about Kennith.
To do this, you have to walk to the fishing platform, and then find the fisherman in his room. Ask him about how he got these powers in Kennith's Concerns and he'll begin screaming and whining like a little child. Make use of your Commorb on him and Savant will find him to be totally normal. Return to Witchhaven and examine the yellow-skinned inhabitants Buy OSRS Fire Cape. The slugs that are in charge won't be getting orders from Mother Mallum. This indicates that Kennith's Concerns were a scheme to deter the Temple Knights and allow the Mother Mallum to flee.