Brace yourselves for these next two, which are some of the worse ones that still must be said. Feel free to give them a higher or lower rank. For this first one, I'm sorry, but I had to, for the Psychic types:
Pokemon: Grumpig
Ability: Thick Fat
Moveset: Psychic/Psyshock, Teeter Dance/Swagger, Grass Knot/Power Gem, Charge Beam/Rest/Trick Room
Rank: C or D
Analysis: Aside from being one of the earliest Psychic types out there, Grumpig really has nothing else to say about it. Its Special Defense is great, and its Special Attack is decent, at the very least. Using the Ability Thick Fat brings this Pokemon resistances to Fighting, Psychic, Fire, and Ice, and if you combine that with the aforementioned great Special Defense, you could make an early game wall out of this. Teeter Dance or Swagger and Rest would be helpful on this set. Of course, you could also try to have an offensive set, since Grumpig has useful moves such as STAB Psychic or Psyshock, Power Gem, Grass Knot, and Charge Beam (for raising Special Attack). If you have a particularly slow Psychic team, you may want to consider Trick Room, as well. Still, once you get to better Psychic types, you might as well permabox Grumpig, sadly...
Alright, now that that's over... Time for more Fairies~
Pokemon: Wigglytuff
Ability: Cute Charm or Competitive
Moveset: (Choose 4 of your liking) Hyper Voice, Flamethrower, Charge Beam, Grass Knot, Body Slam, Play Rough, Perish Song, Wish, Misty Terrain, Disable, Hidden Power, Swagger, Attract, Charm
Rank: C or D
Analysis: As of E15, Wigglytuff is going to be your first choice in a Fairy Monotype, seeing as there are no others left before Julia. Now, being partially Normal type gives Wigglytuff an advantage over most Fairies: its extensive movepool. Wigglytuff actually has some decent Attack and Special Attack and great HP, so it actually can make use of any of the following: STAB Hyper Voice or Body Slam, STAB Play Rough, Flamethrower, Grass Knot, Charge Beam (more Special Attack boosts), Perish Song (wonderful for dealing with the last Pokemon of a Gym Leader or a Rival or something), Wish, Misty Terrain (to change the Field), Disable, Hidden Power, Swagger, Attract, and Charm. Competitive could help if you wanted to run a set like Hyper Voice, Charge Beam, Flamethrower, and Grass Knot/Hidden Power, and Cute Charm could just be used for the occasional event where there's a particularly annoying Pokemon opposite of Wigglytuff's Gender. Something to note about this Pokemon is that slapping a Focus Sash on Wigglytuff and having Perish Song means that "impossible" fights like Solaris' Garchomp are pretty easy. Still, Wigglytuff will probably be replaced very soon in a Fairy Monotype, having terrible Defense and Special Defense and Speed. But you'll enjoy those moments of "YOOM-TAH" while they last...