Norse Mythology/WMG

Baldr is evil
His death was actually a My Death Is Just the Beginning, manipulating Loki into killing him. Once on Hel, he convinces her to state that she'll free him if everyone and everything cries for him (having a tremendous egocentrism, its easy to see why); he also asks for Hel to say to her father to disguise himself and not cry for him. However, what Loki didn't count on was Baldr communicating to the messangers of the gods (Odin's ravens most likely) saying who Angrboda really was, ending with the poor god suffering with the snake venom and all. Meanwhile, the gods gets sad and paranoid, and Baldr gets to build his armies. Eventually, he might send someone to free Loki, or somehow Loki frees himself, and in either case Baldr offers him the armies as a "gift for getting punished". Afterwards, Loki dies alongside with most of the army and nearly all of the gods while Baldr becomes the sole governor of the world!

Niddhogg is Satan
If the idea that Norse Mythology is a prequel to Christianity was to be used, Niddhogg, the last surviving dragon, could very well be what we know as Satan, what with Lucifer being a dragon in the Apocalypse and all. Following the idea, Baldr is Jesus.
 * Christianity formed out of Judaism in modern day Palestine, on the east coast of the Medditerranean Sea. Norse Paganism formed in Scandinavia, in the far north of Europe. The idea that Norse Mythology, or any indigenous faith for that matter, is in any way a prequal to Christianity is bullshit the early Christian Church came up with to make pagans convert.

Loki was planning everything from the start
Loki is supposedly a pal of the Aesir before his Heel Face Turn, helping them out with brains when brawn wouldn't cut it. But notice how a lot of his schemes end up with a Jotunn chieftain (such as Thrym or Thiazi) ending up dead. It's like he's deliberately creating a power vacuum that he (the son of two Jotunn remember) can step in to fill. Ragnarok is essentially a rebirth myth, with a new world rising from the ashes of the old, so he could know that his role in bringing about the end of the current role is essential and be making early preperations for it just as Odin was.

All that stuff about the frost giants being stupid and ugly is Trash Talk and propaganda on the part of the Aesir.
Although the frost giants aren't described very positively on the whole, whenever anyone gets up-close-and-personal with them they're often exactly the opposite.

Vast numbers of people are descended from Loki, both paternally and maternally.
And that's why there are so many trolls on the Internet.

Loki is a Papa Wolf and a Mama Bear combined.
And part of the reason he sides with the giants in Ragnarok is because he's not happy with how his kids have been treated.