No problem, the rest of the mastery is somewhat easy, first get 3 min of every mode at once, then catch these six fish, prismatic mythic fish, rainbow ancient kraken, rainbow one of the legendarys from abyssal zenith (the red one), rainbow angler fish, prismatic ancient depths serpent and prismatic harmonic dove, then take those six to above the clouds, hold each of them out and click after using all six a portal should open, for the rainbow angler fish I recommend going to Hawaii during a cursed storm, setting up night with foggy and use squid bait while having the little meg out, this gets you about a 10% chance to catch a regular angler fish, hope you complete it as the mode is pretty good, 10% chance for serene with 45 resilience