I nickname pretty much every Pokémon I catch, atm I have a team on Pokémon White (action replay'd in, caught them all at the beginning, will be my team throughout):
Shellgon lv30 named Ryuujin
-literally translated from kanji to romaji as Dragon God
-IMO Salamence is by far the most impressive and most Dragon-like Pokémon there is, so it is fitting.
Gabite lv32 named Sametatsu
-literally translated from kanji to romaji as Shark Tornado
-fitting IMO due to the extreme speeds and shark like appearance of Garchomp
Deino lv33 named Kurairyuu
-loosely translated from kanji to romaji as Corrupt/Dark Dragon
-somewhat generic, but speaks good in Japanese IMO
Dragonair lv32 named Oni
-means 'Ogre/Monster/Demon' (Japanese)
-not the most fitting name but it was more inspired from Oni Akuma from Street Fighter, a large, all-powerful magical behemoth, very bulky and powerful like Dragonite. Oni Akuma is also inspired by Buddhism, which is largely viewed as a peaceful, docile religion, which I believe is fitting for Dragonite.
Charmeleon lv34 named Kakitaiki
-combination of Kaki (a semi-famous Fire-bellied Newt in Japanese folklore, also roughly translate as fire in Hachijō) and taiki (which means air, not oxygen, but the very essence of all the air (oxygen, methane, cdoxide etc.) that surrounds the entire planet). Fitting for Charizard IMO but wouldn't mind renaming him soon.
Axew lv34 named Ikari
-literally translated from kanji to romaji as Anger
-very fitting considering his extremely high attack stat
I don't normally go with Japanese nicknames as I find it incredibly weaboo, but I decided on an all dragon team for a challenge (1/2 EXP cheat, infinite PP cheat, no Pokémon centers, Nuzlocke rules for death, customized movesets from the start) and the first one I chose was Dragonite, I was thinking about naming him Oni for the reasons above and it stuck, from that point on I decided to use Japanese names for the nicknames.