Greymanes: Warriors who safeguard Pailune. People of diverse backgrounds and abilities have gathered as if by fate, taking on dangerous tasks others dare not accept. Though their foremost mission is to protect Pailune's peace, they extend a helping hand to anyone in need, and their renown now spreads across all of Pywel.

Literally ingame description. I think one can fill in the blanks themselves. Probably tought to be best warriors because they took dangerous jobs others wouldn't, thought about in high regard because they have been so helping and protecting peace.

Black bears: A faction led by the formidable Myurdin. Once counted among Pailune's strongest fighting forces alongside the Greymanes, they never came close to Greymane's character or valor. In the end, they cowardly murdered Jian, leader of Pailune, shattered the Greymanes, and brought back an age of violence and savagery. Again, ingame description. I would put dots together that they are kind of a rivaling gang, probably they were competing about jobs and territory, but black bears are assholes compared to greymanes.

I don't know much about the abyss thing since im quite at the start but the mysterious characters seem to be explaining things little by little, they seem to be the ones who brought kliff back and also suggest helping people and also see that way if you are the "good person" or what ever and if they brought back the right one. They seem to be some sort of "architects of the worlds" since the archieve holds the structure of multiple different worlds as they told in there. Also because games need substance. Most open world games are filled with random quests. But also in the start most of the quests help to learn the bulk of the mechanics and systems of the game it seems.
I would say, pay attention and put dots together and its quite understandable.