Quoted By:
Seaking lvl 38
Horn attack
Waterfall
Aqua ring
Super sonic
Poliwhirl lvl 40
Ice punch
Body slam
Hypnosis
Belly drum
Azumaril level 40
Attract
Dive
Aqua tail
Roll out
Seadra lvl 41
Smoke screen
Bubble beam
Agility
Dragon breath
Walrein level 44
Snore
Rest
Water pulse
Aurora beam
6-7 gym based on status effects water pokemon. Each pokemon has some way to cause status problems. One pokemon has a move it's too low level for while another has 2 water movies. It's the kind of decisions we see in a lot of gyms where it doesn't make sense to the player. All of them have potential to be trolly where they can do a status and then build up a rollout or belly drum. All are common pokemon you would find in water around the gym except Walrein who would be an exotic pokemon from an ice dungeon after the gym. Rest is there for a "positive" status when he falls asleep.
For hard mode drop Seaking, add lanturn and quadsire. Laturn is a fucker who can spam every status that annoys and quagsire is tanky and learns toxic naturally.
Gym leader would be a confident fishing village diver. He would gloat how he's going to show you the power of status effects and beat your team while they're helpless. His back story would be a naturalist who protects his local eco system from dangerous invasive species (sharpedos, tentacruels etc.) He uses status to disable them and move them from his village.