I love nicknames. I usually name the ones I'm particularly fond of. Or in the case of XD, I named them all.
Just a few names I've given:
Yuci- Empoleon
Sandi- Lopunny
Yeigou- Roserade
Esdi- Rampardos
Uii- Milotic
Muny- Munchlax
Cei- Dialga
Ri- Riolu
Mattress- Snorlax (Trainer's Mattress was burned! x3)
Mekiu- Mesprit
Yora- Azelf
Tuye- Uxie
Paperclips- Magneton
Bahamut- Rayquaza
Mr.Wiggles- Rayquaza
ImAFairy- Rayquaza
Aeon- Blaziken
Un-Articuno
Deux- Zapdos
Trois- Moltres
Rrisg- Regigigas
Celeste- Rotom (From the Mary Celeste tale)
Aeth- Kabutops
Auque- Omastar
Aerre- Aerodactyl
Yukonna-Froslass
Cioci- Umbreon
Psaika- Espeon
Dicet- Glaceon
Khemst- Flareon
Einjyn- Jolteon
Sieco- Vaporeon
Mary-Mareep
Pyrra- Anorith
Giya- Lileep
Buu- Hariyama
Eteau- Leafeon
(Genders?)
Yuci - 5/10 Original, but I don't think it fits an Empoleon well. Maybe if more was added to it?
Sandi - 8/10 Not very original, but fits a Lopunny well.

Yeigou - 10/10 Original name that looks interesting too.
Esdi - 7.5/10 Again, unique name. A little "soft" for a hardy Rampardos, but I like your style.
Uii - 2/10 Very strange sounding and looking. I don't think it fits a majestic Miltoic at all!
Muny - Cute as a Munchlax but It'll be a Snorlax so... 6.5/10 Still good as a Snorlax name, still fits, but not the best.
Cei - 4/10 Again, I like the creative direction, but a simple name doesn't fit a legendary dragon. If the name were more complex then yes.
Ri - Remember its not a Riolu you're naming (unless its a Little Cup Pokemon) its a Lucario you're ultimately naming. In this case 7/10 A sharp name like this works great with a fighting, regal Lucario.
Mattress - Is it female? Ok if female, still a really weird name...lol. Uh, 5/10? I almost didn't rate this though haha.
Mekiu - 10/10 Fits it perfect!
Yora - 10/10!
Tuye - 10/10!
Paperclips - 1/10 Just...no. :x Things as names (like mattress) not to good usually.
Bahamut - 10/10 Great muscly name for this dragon.
Wiggles, ImAFairy - 1/10
Aeon - Cool name for a cool (hot?) Pokemon.
Un - 1/10 Just doesn't work for a majestic legendary bird. Sounds bad, looks weird.
Deux - 1/10 Same as above, (since its ultimately a cooling looking "Do")
Trois - 2/10 Looks nice, but doesn't sound great.
(Yes I get the 1, 2, 3)
Risg - 4/10 Interesting, but the flow of the name just can't get pulled off.
Celeste - 9/10 Great nickname, but for a Rotom? Sure.
Aeth - 6.5/10 Looks cool, but the "th" kinda ruins it. Its dull for a sharp Pokemon!
Auque - 9.5/10 Nice.
Aerre - 9.5
Yukonna - 10/10
Cioci - 7.5/10
Psaika - 8/10
Dicet - 3/10
Khemst - 4/10
Einjyn - 10/10 Love it.
Sieco - 7.5/10
Mary - (Ampharos) 3/10
Pyrra - 10/10
Giya - 8/10
Buu - 7/10
Etaeu - 8/10
Waaay to many names to give individual detail, hope you understand.