Hey people!
I know alot of you are looking for how to fix the underlight Angler, I never really post here but this puzzled me for so long that I had to share this!
The abilities are still obtainable in the war within (the artifact power is spendable)
When you get the underlight angler on a fresh 80 toon you can get the addon Plumber. This fixes the UI for the angler.
Now to add artifact power you need to unequip the fishing rod. Equip an actual artifact weapon and go to the forge. There you first open the tab of your artifact weapon and close it again.
Then you shift click the fishing rod from your bag. Boom you can spend your well earned artifact fishing power! Immidietly unlocking the Undercurrent ability.
Enjoy, I hope u find this post so it saves you alot of trial and error!