The lineages are inherited randomly, as such a child born from two different lineage isn't limited by those lineages in any way. there are very few exeptions to this rule. the demon king's lineage is an example as he is hereditary. Because of this system a demon's genome will undergo heavy changes during the awakening wich is why genetical diseases are inexistants in the demon race. 

before a demon awake his lineage he is extremely weakened and his body isn't capable to support any kind of training. as such the awakening of the lineage is one of the most important event in the liffe of a demon. with the awakening of their lineages demon gain some special traits and caracteristics coupled with an overall improvement of their capabilities. as such they become able to train. however lineages have little to none impact on the mind because they are awakened  at 4 yers old, after the child has already formed the base of his personality. however there are still lineages with strong personality traits that can impact the newly awakened demons.

The number of lineages can vary as sometimes demons can creat their own lineages, little is known about how it's possible but it is believed that the direct intervention of a god is the source of the new lineages. similarly lineages can evolve when a child has already aquired a major talent or has a strong enough mind that a part of it is imprinted in the lineage

the demon king's lineage strengthen the overall growth of the child and strengthen his natural dispositions. through the horns mainly.

for a wizard the horns would act as mana batteries, a warrior would become able to alter their size and weight and use them as weapons, a more dexterous demon king could have poisonous or whip like horns. however it's necessary to keep in mind that each demon king's horns are unique to him even if they are often similarities.

the demon king's lineage also strengthen one's intelligency without affecting their physical bodies. and make them able to use the war knowledge of past ancestors.

recently the demon king's lineage has been changed by his possessor wich resulted in it being linked to the symbios lineage by a love binding wich will be passed on between the two lineages.

the symbios lineage is a recently born lineage wich started with the second born of the demon king Terith.

this lineage include two main skills wich are the [energetical spell eyes] skills wich allow one to store magic in his eyes and directly see the flow of energies like mana, ki or aura. and the [symbiosis] skill wich allow them to form a sybiotic relation with a parasitical being. it wouldn't be that powerful if the blood centipede wasn't a possesion of this lineage. it's a parisitical being wich feed on blood and use it to strengthen his host. it can even go out of the host's body, but still need to be connected to it, and act as another limb.

this parasite isn't a part of the lineage but can be passed on between memebers of the lineage. as such it is believed that the symbios lineage can only be posessed by two people at the same time. very much like the demon king's to which it is linked by a blood link.