>>724552078
Yeah, Eldar Cosairs are an odd Rogue Trader artefact from back in the day, but they are like Rangers in that they are bored Craftworld Eldar who find life stifling, so join a crew to sail the Galaxy and pillage Human worlds, but they aren't enslaving or sadists like the Dark Eldar.
Warhammer Fantasy also had a similar group of Elves called the Sea Elves, which were more adventurous High Elves that lived on the coast or in coastal Enclaves around the World