You'll have to go to the border of Neon City and Forbidden Spires, make a plasma stream going into Forbidden Spires and then you can be able to fish for the Lionfish. As far as I know, there aren't any Lairs or Dungeons with the plasma so you'll have to do what I explained.
If I'm wrong about there being any plasma in dungeons, let me know.
I am known as SkyTheVirus... or Commander Vitus. A well known Trove Artist who is also a virus :P jk...
Check out all my other art on my DeviantArt!
I do Commissions! If you would like to request a commission, click this button!
Before you reach Mastery 20 by using SkyTheVirus's Refer-A-Friend Code
No Link Set
This user has not linked their Trovesaurus account with their TroveTools.NET mod loader.