I think people might be mistaking "cutesy and girly" for fairy-esque creatures based on what we've seen so far. Fairy is a very diverse category ranging from adorable little pixies and sprites to creepy bog monsters and children eaters. We just happen to have only seen cutesy ones so far, excepting Xerneas. Marill seems like a logical thing to me, it's a spritely water pokemon, so no issues there.
I DO agree, though, and hope that we get a really interesting new Water/Fairy, preferably something elegant looking with flow-y fins or something of the like. I'm very intrigued by the new type, and I'm kind of hoping based on the fact that we now have a Psychic/Dark pokemon, that they'll use this generation to fill in the gaps of unused type combinations that we haven't had before. There aren't that many, and there are plenty of interesting type combos that I think it'd be easy enough to fill out the dex and give us the rest of the available pairings in one go. Not only am I kind of hoping that we'll see each type paired with Fairy (Sooooo wanna see what a poison or dragon fairy would look like), but you know you all wanna see a Fire/Ice type just to see how they'd do it.
And they better add the Sing and/or Perish Song move to that Water/Fairy Pokemon.
When I think Water/Fairy, I kind of picture... Maybe a translucent Jellyfish that seems to be almost made of water?
Jellicent exists though. So nope.
What about Round? XD
People use Round?
Nah, I just remembered that no matter how terrible it ended up, Sing a Round (what people translated it as before the official translation) was an awesome idea (reminds me of the "Irish Drinking Song" game from Whose Line is it Anyway?).
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