CORRUPTED VETEHINEN

(and here I wrote too long comment...)

damn thats one nasty beast. guys be like 'what in Ukkos name did we just summon' tho i imagine really any creature in Finnish mythology doesnt mach to Tursas.

(personally always imagined tursas looks like something from lovecraft. since it being one of the first beings, both powerful as god and pure evil, enjoying to witness how people suffer of diseases he creates. tho he is also worshiped as god of war. tho I guess that fits well in his image since war sure causes suffering to mortal beings. guess blessing of other gods will protect you from both your enemy and tursas of turning on you at the end making someone slay you) tho his followers are usually merely called 'evil creatures' its pretty vague on what they might be. pretty much just one witch is mentioned who brought Tursas some splinters from the tree that grow in the beginning of the world. and his three sons, but there is other origins given to them also.
most likely they are other creatures of Finnish mythology or some that arent even named other than 'evil creatures' so they are some indefinite horde that consists of all sort of creatures, like giants, maahinen (or right down goblin since so much similar that possibly just different name to same creature) witches, trolls, humans, and other beings that either serve him directly or he works through them. most likely all corrupted and so deformed that its hard to tell what they have been in their earlier lives and thus earned the name 'evil creature'
 
tho dont know where realm of Tursas could been. underground was believed to be home for creatures like maahinen but even deeper there was underworld that was a scary place. humans exist there in forms of spirits and ghosts endlessly wondering. and same fate follows for both good and bad people. and there is powerful guards looking after the dead so they wont escape. tho some have since there is all sorta ghosts in Finnish mythology wondering the cemeteries and other places. living may travel there, but it will take weeks journey through wilderness and finally crossing the river with help of ferryman. but its worth it since there is information and powerful spells to be obtained from there. shamans may enter the realm in trans, they fool the guards that way and may return to their bodies. Väinämöinen did they journey and had hard time leaving from there, only by turning into snake he could finally escape. and like being dead wasnt enough, there is Tuoni the god of the dead and his wife Tuonetar ruling over the dead. tho dead may return to realm of the living and turns into protective spirit for their children and so on. in some stories there is fiery vortex called Kinahmi which is full of blades and swords. so there really wasnt valhalla for our honored dead. in some cases Tuonela is pointed to north, but there waits a giant serpent who protects the gates of north.

tho since other gods live in sky, or in water, or in forest. could assume that even that Tursas is not really a god. he would have similar doorway into his realm. probably in some deepest darkness of the world is some necropolis that he has made his home full of his minions ready to maim all crazy enough to go there, letting only the followers of Tursas through. most likely they dont have to even think that much which one they are since they possibly are already starting to show physical signs of corruption (like swarm of tentacles bursting through eye socket or some other easily noticeable form of corruption) and possibly the more corrupted they become the more inhuman they also sound like. the ones who could talk probably sounded incredibly horrifying, not to mention that anything they say isnt worth hearing if you dont wish to worship Tursas. since our mythology was pretty much a memory based and we didnt really write. so anyway you could start worship of such a being is by hearing from it and than seeking out a mentor, who most likely is in hunt of new followers for Tursas. most likely they also serve him after their death. would think witches at least return as some liches and others as ghosts or undead. or at least those who arent corrupted already in so deeply that they can escape death and even that they gain age they also gain power in return and even hundreds of years old they still go on even that their muscles and tendons are broken over age and corruption. but it only pleases Tursas to see their suffering. and no matter how much they suffer they never question him. tho suffering has not turned into pleasure for them and they indeed are in great pain all the time. but it has become normal existence for them and their twisted minds dont know to question, nor question even if they did know.
tho Tursas is meaning to destroy the world at some point. he tried ones already with his sons and failed at the end (splinters of the tree were turned into arrows, one fired to ground, which shake and crumble. second to sky which almost collapsed. third was supposed to fire to iron mountain ending the world but instead, the arrow ricochet from the mountain with out harming it, and so they had failed) but with a massive army of willing slaves he can pretty much destroy what is left from the world. possibly waiting for the man to become weak before striking. pretty good its mythology since sure dont wish that kind of stuff being true. world is horrible enough with out some chaos god.