@Barhandar  
Okay, Amber makes sense now. Thanks for that. And I guess the artist didn’t know about Trinket’s plating. Though I still wonder who Ilygredd is. I know she’s the giant alicorn, but what’s her story?

@Wiimeiser  
Hindsight makes elimination much easier.
 
Amber (Gem) is the all-amber colored pony on the left and Trinket is shiny yellow blue-eyed mare in the middle. Who needs some more robot plating joints for obviousness!

@Trini  
Makes sense in hindsight, given her cutie mark…

@Wiimeiser  
I will say, Jade Alloy is the pony in the bottom right; only cause shes my pony. The one with yhe anvil as a cutie mark

Let’s see:  
Amber- Is a common enough OC name that it’s impossible to tell except by process of elimination or asking the artist  
Cirrus Mist- Brown pegasus above the changeling and below the giant purple alicorn  
Copper Sparks- Mare with goggles in lower left  
Deadeye- Batpony with eyepatch  
Elytrius- Changeling  
Gallant Hymn- Stallion on the left with compass cutie mark  
Ilygredd- giant purple alicorn  
Jade Alloy- Impossible to determine  
Lime Sapphire- The gooey green pony  
Night Light- Black stallion below Lime Sapphire  
Pepper Spice- Brown guard  
Shani- Black pony in bottom left with screwdriver  
Swift Justice- White guard  
Trinket- Is a common enough OC name that it’s impossible to tell except by process of elimination or asking the artist
 
So that’s three OCs who can’t be named. Also, this would be easier if we had notes like Danbooru…