Basic run-downs of the Chapters I understand:
- Ultramarines aren't actually as bad as the memes make them seem, they're just super proud and other Chpaters are salty because their leader wrote the Space Book and they hardly ever follow their own rules.
- Dark Angels fight tooth and nail to keep the fact that their home world was deleted a secret and will exercise EXTREME PREJUDICE on the enemies of the Imperium, especially those who follow the one who killed their planet.
- Salamanders (shown here) are pyromaniacs, but they're nice pyromaniacs. They will burn down your peasant-class farm situated on a poor backwater planet on the outskirts of the system, but that's only because they have a much better, bigger, higher-class home prepared for you on a richer planet closer to the heart of the Imperium, and they're just helping liquidate your useless assets.