Freyr is destined to face a colossal titan of fire threatening Midgard the realm of humans and has a sister called Freyja who is considered goddess of War.
Prose Edda states that some Gods (Among them Thor, the strongest of all Gods), travel through the outskirts of of Midgard where a devious hairy titan strolls around and encounter it ending up at Utgard.
There is no Human-Titan community in the Norse but we can pinpoint them to characters, for example Vidar was a Half-Titan known for kicks.
According to the Norse, Midgard has no knowledge of the other communities except for the Titans.
I also think there might be other community aside from the walls of maria and etc.
i would like to share my theory for shingeki no kyojin, possible spoilers hehehe
Maybe the reason why reiner and bertholt and annie' wantto let The other titan to devour humans so that humans will not suffer the same as the titan is experiencing What i mean is that maybe there is GOROSEI like leaders that just experementing those humans inside The wall,injecting humans to become titan long ago,just like what eren's father did to him,and by that maybe the Government uses titans for war,as a weapon.and they use those like the types of eren,reiner etc. And those titans who enters the wall are the failed experiments. They are the castawayed by the goverment. And by the way maybe eren's father is one of the top scientist of the government and i think hes the one behind the transformation of reiner and company ,this is just my theory.
I don't think that at any point humans will be able to properly interact with titans.... Titans are agressive and mindless in 99.999% of the cases so far and they seem agressive even towards other titans considering they attacked the colossal titan and eren. I do think it is entirely possible there are other colonies around however I think the deal will be different.
My impression is that in the grand scheme of things what is going on is basically a huge experiment, an experiment for human evolution with titans being the next step so to speak. We know for a fact that humans turn for some reason into titans. The fact that a couple of them seem to have for a short period of time a semblance of their former self is evidence enough of that. So basically you have an experimental procedure to turn humans into titans however you have a extremely low success rate. In most cases you see this mindless beasts but perhaps in a sort of virus immunity fashion you have anywhere between 1 and 0.0001% of having a human succesfully mutate into a titan. The ones behind this seeing that without humanity there would not be a titan future so to speak decided to isolate human "breeding grounds" where they would be safe from the extremely powerful titans and perhaps even the infection to some extent where the human-titan population would increase until there were enough of them for them to be able to exist successfully as a race. Perhaps the recent outbreak of titanism so to speak was a result of the wall being broken.... The titans in the walls would be the original human-titans who took one for the team so that the new human-titan specie could have a chance. humans seem to have been more numerous before the original outbreak of titanism so perhaps with human population being in the billions or so even with the extremely low rate for titanism it would be possible to gather a few thousand titans to create the walls and perhaps a couple other countries.
Then with that in mind the wall serves another purpose. The wall protects humans from titans but it also severely limits them. It limits the amount of resources they have at any given time and by extension it limits the amount of humans there can be at a time. We even know people have been sent to their deaths just to avoid having to feed them which is cruel but considering the circumstances it was either that or widespread misery. The church and perhaps the never seen royalty are another method to keep people in place. It keeps the population within the walls until the day the titans within them can wake up and do away with humanity. Of course if that is the case then quite a few people within the church and royalty must be titans.