WIP (1/3)
Grisailleon
Pronounced: "Gris-aye-leon"
A combination of grisaille (gris-aye), a classical method of painting in black and white, and leon meaning lion.
(In the grand tradition of Pokemon with ambiguously pronounced names, "Gris-ei-leon" is also probably an OK pronunciation, since it still sounds good. I also considered Grisailleo, and would be interested to know if people have a preference.)
WIP (2/3)
Chimeroscuro
Pronounced: "Chi-mehr-os-kyu-ro"
A combination of chimera and chiaroscuro (the use of strong contrast between light and shadow to create depth in a painting).
(I'm a little surprised this hadn't been suggested already, maybe I just missed it. It might be too complicated to be a good name, but I thought the concept of light and shadow played well into the Dark typing.)
WIP (3/3)
Atroxic
Pronounced: "At-rocks-ic"
A combination of atrox (from panthera atrox, an extinct species of massive lions once native to North America) and toxic.
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Maybe I'm a giant art nerd, but once I started looking I had a lot of ideas for this one.
First of all, I'm upset that the Latin name for lead is plumbum. Lead has such a history as toxic pigment. Sadly 'lead' is almost too short to work with and any combination I came up with that involved 'plumbum'. . . well, the syllables you have to work with are 'plum' and 'bum'. Good luck making that sound serious.
In more promising territory, two arsenic-containing pigments used in ancient Egypt have very cool names -- orpiment and realgar. Maybe somebody more creative than I can come up with some combo with one of those that (a) actually sounds like a Pokemon name and (b) isn't a complete phonetic nightmare. (Honestly I think realgar would be a solid name by itself, because 'real' means royal in Spanish, but I wasn't sure if submitting the name of an actual object was allowed.)
On a feedback note, I like the idea of this name being a little more complicated or dense than other CAP names, since it's supposed to have mythical or legendary vibes and usually their names aren't just combinations of common words. I also think the idea of it staying the same in multiple languages is interesting, but I'm not attached to it because I don't want to be unnecessarily restricted to only Japanese names.
Sorry for the long post, hopefully this doesn't clutter up the thread too badly.