Onyx def need a boost. organics can greatly outbreed them, and Yor can use all its citizens right away and then build more pretty fast, assuming they have good durantium and production. Here's a few ideas i had for them...

1. Put promethion in their starting star system.
- It's the rarest resource in the game and they need it really bad and have no other reliable way to get it.

2. Make their starting world Low Gravity.
- Their lore already says they love low gravity environments, and they could really use that manufacturing boost. A tile that adds promethion every month would be very nice too, and would make a lot of sense considering they travel around a lot and are always looking for promethion.

3. Change their 2nd ability from Experienced to Archeologist.
- They don't really need Experienced, and their lore says they love being on asteroids, and the policy that archeology adds increases asteroid production by 1.0, which the onyx really, really need to make up for their super low growth rate starting out too.

I tried a game with #2 and #3 changes made, and they did much better in the early game, and it was the first time I felt that they might have the potential to compete with the other races.