>>85002703Blood Angels are one of the most selfless chapters that go out of their way to save civilians. But they have a dark Chuuni curse. They all eventually go insane from the psychic vision of their Primarch being killed by Horus, and even before the insanity they have bloodlust unlike other chapters.
On the tabletop you can field squads of the insane brothers in their black armor, they basically get extra attacks and ignore wounds, but are forced to charge into the closest enemy they see, depending on the edition.
Other than that Blood Angels got a lot of unique rules like being able to take heavy flamers in tactical squads, or special melta pistols that other chapters didn't have access to or having spellcaster dreadnoughts that could fly, their personal version of the Predator tank that could take super flamethrower turret or twin gatling cannons. But a lot of that didn't make it into the newest edition because GW did a line refresh and they make the same infantry and dreadnoughts for all the chapters now.