I’ve seen reference that this cover might have been colored by Marie Severin. That’s possible; she did many cover layouts and was the colorist at EC. To me, the colors here look like the classic muted tones of Stan Goldberg, who was the main colorist through the Atlas Era, pre-Marvel’s monster books and the early Marvel Age. He stopped being a freelancer for Marvel in 1969, so the dates match up.
All these reds and yellows on one cover really bring out the cataclysm of Thor’s final battle with the malevolent Mangog.
Balder still braves Karnilla’s Lost Legion, cursed to serve the Norn Queen until Balder’s nobility breaks the spell. Now with these long-lost Warriors at his side, Karnilla dispatches them back to Asgard to face annihilation at the hands of the monstrous creature of hate and carnage.
Mangog shrugs aside every weapon, every power in the Realm Enternal and finally grasps the Odinsword. Drawing the mighty weapon from its hilt spells the end of all things.
In one of the weaker wrap-ups of all time, Odin appears and the Odin spell that bound the race into Mangog is undone. The once mighty beast is but a ghost fading into the cool stone beneath Asgard. (I guess someone forgot that Mangog told us his own race forged the vessel of vengeance themselves, not Odin, just two issues ago. Perhaps Odin only wanted them to think it, so that when the incandescent fury of Mangog was at his zenith, when the collective power of a billion billion beings was at hand, Odin could crush it utterly by dismissing the binding spell and their memory, exhausting their hatred and battle lust for all time. Do I win a belated No Prize? What say you, Mr. Lee?)
Even with the anti-climatic conclusion, this is still one of Thor’s all-time stories. It looks fantastic in the King-Size Kirby Edition, which dwarfs these old but beloved floppies of mine (comparison pic coming up).