Sounds suitably epic. I feel like the Artificial moon needs a name. How about Larberec, or Xetroc?
I like this. It shows how much Dekon and Arrusif cared for each other that Arrusif could trust his friend with this sort of task. Although it also tells me that Dekon was okay with screwing his friend's legacy over. Also also, 5 years? I find it difficult to believe that in only 5 years everyone forgot Arrusif's name. What about all the people who were still alive 5 years previous? Short attention spans? It might be a better idea to delay Dekon's successful resurrection of his friend to 50 years at a bare minimum. I'd recommend closer to 100 years, or even more if Obsid convinced Dekon to hold off until Arrusif's name had been totally destroyed.It's true. They did think up the idea of godhood almost as soon as Almantha came into sight...Also, Arrusif made the sacrifice to not become a god willingly, and what really got him is that he was essentially erased from the history books, no tragic deaths before the day of apotheosis, no mention of Arrusif the master fire mage and illusionist, no nothing.
To make this a bit more plausible (and, I think, more compelling) why don't we have it that Arrusif didn't know for certain that Dekon would complete the lichification process? He knew about the spell to bring his mind back (he wrote it himself), but he didn't know if Dekon would a) cast it or b) be able to prepare and perfect the vines puppeteering his body. Well, he didn't know per se, but he trusted Dekon, who came through 5 years later.
Also, besides being allowed to live a bit longer (plus the lichification), what did Arrusif get out of lichdom? Did he really expect for Obsid to take his place in the Minds and keep using the fire mage's name? Did he believe Dekon could restore his flesh so he could go out in the daylight? I think it would be good to have Arrusif's idea of The Plan, just to see the true extent of how divorced his expectations were from what ultimately happened to him.