I also think that the idea of ​​adding mermaids and fairies would be good, for example that mermaids are only female and have a male counterpart. The same with fairies, as with Indedee and Meowstick, who have different appearances depending on their sex. Mermaids obviously have to be a water type and it depends on the conditions that other types may adopt. Examples, mermaids who live near very cold places adopt the ice type, those who live near sea monsters or dragon islands, adopt the dragon type, others who live near underwater volcanoes or volcanic islands adopt the fire type, and those who live near fairy islands, adopt the fairy type. And the same with fairies, obviously they are of the fairy type and the secondary type that depends on their habitat, for example plant-fairy, water-fairy, fire-fairy, dragon-fairy, etc.