Sigurd’s Bane

" He always loved blood "

I think this should either be "He loved blood..." or "He had always loved blood..."

Couple of suggestions:

<Perhaps they are cursed by the gods. Perhaps their souls are warped, or maybe they are plagued by demons >

You have a nice rhythm based on the reptition of "perhaps." I would encourage you to use it all the way through the sentence. So instead of perhaps . . . perhaps . . . maybe ; you'd have perhaps . . . perhaps . . . perhaps.
I hope that made sense.

My second suggestion involves point of view ("POV"). The paragraph currently seems to be coming from an omniscient, godlike POV. And it works fine that way. But it might be more interesting if it came from the POV of a particular person.

I say this because the first line makes a very definite moral judgement. It's fine to set that moral judgment as truth in the world of your story--but it might be more interesting to see it come from a character. Especially considering how strongly the point is stated.

Would it be better as "His father tried to control Ogrimm's violent tendencies" or is this too picky?

I also like the overall rhythm.

I suggest making the statement come from the POV of a character not because I or anyone else agrees or disagrees with the moral judgment it makes. I think such absolute moral conviction, stated as fact, would make for an interesting and compelling character.

Nice. Are you looking for people to read more? How much (by word count)?

I'm willing to accept the moral statement for the purposes of the story--though I don't necessarily agree with it. And I'm not particularly in agreement with the others above to focus in on a POV character right away. I think you can bring in the POV character in the next paragraph or two and still be able to maintain the integrity of what you have here. It is not outside the realm of style to begin a scene with a few paragraphs of Omniscient before zeroing in on a POV--in fact, it's quite common.

What I would really like to see is a progression of atrocities as Ogrimm ages. Show me what he would do as a baby, then as a boy, then as an adolescent, rather than a series of examples that could have been done at any stage in his development.

And I definitely disagree about there being no absolute evil. I have seen it.

As for being born evil...as far as you describe this, that pretty much fits all humans. Children love to inflict pain and they adore the sight of blood from infancy. Most of them grow out of it fairly quickly, but a mother that encouraged such behavior would probably stunt that particular aspect of moral development. It is a bit curious that any mother would encourage a child's natural ruthlessness, since mother's are the primary victims of infants.