Hello everyone and welcome to my 86th analysis, this time featuring Watinhart.
Even though the Wiki has it wrong, Rainbow Revenge is indeed an AOE attack, which makes Watinhart so much better as an attacker. The said move has 45 Base Power, is unresisted and applies the Water version of Sticky Lava on all enemies! Not only that, but with his decent Life, immunity to Freeze and Life Steal/Shield, Watinhart is a chore for Water monsters to deal with, and even in the Sea book he fares greatly. However, Watinhart is slow and wants more than 4 moveslots.

-Rainbow Revenge
-Six-Pack Rings
-Antarctic Water
-Gun Shell/Prestige Oil Spill
Runes: 2 Strength 1 Speed

Rainbow Revenge has the golden 45 Base Power, is unresisted and makes all enemies very weak to Water moves-the perfect support for Six-Pack Rings, a 40 Base Power AOE Water move. Antarcti Water is a single target Freeze which is always good to have. Lastly, Gun Shell deals the highest amount of damage out of all his moves and gives him a 30% Life Shield, but Prestige Oil Spill synergises with Rainbow Revenge and heals more, albeit it can't heal excess. 2 Strength 1 Speed is an attacker's general spread.

Teammates: Watinhart functions well on his own, though Demise can help greatly after Rainbow Revenge is used. Other Water attackers like Hydrok the Forgotten can take advantage of Rainbow Revenge, in which case using 2 Speed 1 Strength on Watinhart could be good-I didn't list this as an option since it's situational.

Countering Watinhart: Watinhart is slow, so Stunning or Possessing him before he moves is crucial. Any form of CD activation is very effective, since it locks down all of his most powerful moves for 2-3 turns. In the Sea book, Hydratila the Boltcaster outright one-shots him.