Understanding the World of Fionavar

"And on the north wind there came then the triumphant laughter of the first and falledn god, who was coming down on them like a hammer bringing fire, bringing war" (The Summer Tree, 166)

I never caught this part of the story on the previous readings, and I always wondered why Rakoth Maugrim was so powerful? Why did vanquishing his forces meant that he would be beaten down and incapacitated? Here was my answer this whole time.

Rakoth Maugrim wasn't just one of the gods who turned evil and corrupt, but he was the first god of all the gods. That's why he's so powerful, such that he has the power to create and to unravel. That's why he's called the unraveller.

When the Bael Rangat war ended, the humans and lios alfar had a lot of help from the other gods. It was Mornir, the god of Thunder, who gave power to the magi to helm their own magic, independent from the wild magic of Mother Earth, Dana. From that release Amairgen Whitebranch was able to bind himself to a human source, Lisen of the Wood. From the magic that they created, the humans had a chance. And in the end, they won the war. They were able to bind Rakoth Maugrim to the mountain, Rangat.

Rakoth Maugrim is invisible until he regained so much of his strength that he was able to materialize as flames and smoke. Otherwise, we can only see him through the people and creatures who work his will and carry out the heinous atrocities under his direction. When all of his carnal subjects were destroyed at the end of The Darkest Road, that stripped Rakoth Maugrim of his powers.