I hate the perishing sight of him. I just had my first post-Trial trainer battle with Hau in UltraSun and his Pikachu almost annihilated me. Admittedly, this is what comes of having a team that is two thirds Flying types but the almost invincible nature of Electric types gets to me sometimes, especially Pickahu with its Static ability that paralyzes you for daring to use a physical attack against the little yellow git.
Ground types, that's the only sort that gets a super effective against Electric.
Guess what type I've never particularly enjoyed using?
Underneath all the bitching and moaning here I do feel there is a serious point here. Pokémon has always had a “play as you like” ethos and, for the most part, you can. Electric types, though, are a very real exception to this rule. Obviously they can be dealt with but it tends to take a lot of Paralyze Heals.
Still, I have plenty more encounters with Hau to work out a strategy.