(Reigar & Mercane) descriptions
I have my book set on the couch nearby, but after my overnight shift in the warehouse, I'm a bit too "lazy" at the moment to break it out.
I know, off the top of my head from the Reigar section, their
ENTIRE thing in 5E was the fact that they genocided their own planet and that they consider all acts of War to be the highest form of Art. IIRC in 2E Spelljammer, The Reigar were basically all about art/making the highest form of it.
The Errata changes it where not ONLY are there Reigar that consider War to be the highest form of Art still, but also others that pursue the highest form of Art via nonviolent/warlike means as well. Which brings the 5E version back around to their aspects from 2E.
I'm not sure about the Mercane. In fact, I'm not sure why they are Celestials now.
Also, the Dohwar sounded like shady Penguin mafia type deal as a group of them are referred to as a
Cartel which brings about all kinds of shady business practices to mind. (Whether they were as deadly as the actual Mafia in that regard, well that's probably up to the DM to decide).