The only problem is that the troll are very different in biology and information regarding what a troll is.
Aye, but it's not a big problem. Let's say that there are as many kinds of trolls are there usually are elves (one for each biome that they can inhabit)such as rock trolls, frost trolls and so on. Krobb would then be a part of the vanilla variant most commonly known as simply "troll". Mog on the other hand would still accurately be called a troll, but belongs to the subclassification "mountain troll" or "rock troll" depending on how the families are named.
Trolls are huge lumbering beasts made of living stone and possessing clearly superhuman levels of strength. What is also clear is their subhuman level of intelligence. While they are nearly impervious to any damage dealt by anything less than siege engines, their size makes them an easy target even for a catapult. The myth that they turn to stone in direct sunlight is based on a grain of truth. Their brains are very sensitive to temperature, and on warm days in direct sunlight they might overheat and forget how to move.
Appearance: While he is basically humanoid Mog literally looks like an animated pile of stones equal in size to at least three or four well-fed adult humans if not more. There are very few doors in Kings Knell that Mog does not have to duck to get through. Instead of hair, Mog has started to grow moss on the top of his head and upper parts of his arms which signifies that he has gone through puberty.
Age: 54 years.
Former Profession: Lifting and holding equipment.
Skill: Carrying and holding heavy stuff without dropping them.
Personality: Mog is not a bad troll. Bad trolls eat people. Mog is not really an especially good troll either, he's pretty average. Not a great initiative-taker, Mog generally responds to people in the same way as they react to him. If they are friendly, he's friendly and will be convinced of his friend's friendlyness. It usually takes a while for a new concept to take root inside Mog's mind, but once there, it's stuck for a very long time. One such concept is the authority of rank, and while Mog may not be the sharpest tool in the shed, much like a golem he would never dream of disobeying an order from a superior officer. Mog is also a fearless creature, it's easy to have no fear when you're pretty much made of stone. He'll wade into any kind of danger without a second thought if ordered to, or if someone convinces him that it is a good idea.
History: Mog was born in the mountains of his people far away from the city. Had he been born only one generation earlier he might not have known more about the world beyond the mountain than the odd captured wanderer would have had time to scream. But times are forever changing. Civilisation creeps forward. For Mog's generation, the mountain was not a place where food and shelter could easily be found any more. He would have to go away to have a better chance to survive.
Mog entered the great city in the same costume as many other trolls, as cheap heavy labour. His first job was simply to hold big wooden planks in place while the real workers worked on them. As time went by and Mog proved himself as a worker who did not drop stuff he found himself in the shipyard tasked with pulling ships out of the water for repairs and doing other heavy jobs. After that companies employees ended up in the guard's cells for heavy embezzlement no one knew what to do with the trolls that technically were not employees but rather tools. As a joke someone asked if they wanted to join the guard, and got a “Ye, sure” as a reply.
Having trolls in the guards has since then proved to be a double edged sword. For one they are a great resource because of their natural abilities. If a criminal is holed up behind a locked door, a troll can generally get it open. They are also able to patrol the slums and come back alive no matter how many times they're stabbed in the back. On the other hand, if they do witness a crime, it doesn't take much for the criminal to convince them that all is fine and to keep partolling.
@GingerBoi123 You're pretty much spot on for what I expect from characters in this game, but could you perhaps define what "unfair" means in Björn's moral code?