Guyssss I tried finding the post where you were discussing the murals but I can't :<
But if you could kindly put up with this ramble then... even though it's probably been mentioned(?)...
PS: Yeah I see the person being strong armed in the titan image too, rofl.

The titan painting:
I know someone said it COULD be Solas, but not necessarily. And this is true, as all the elves we saw in the temple of Mythal were just as eggy as our favorite bald boy. But the man in the painting lacks vallaslin, so I think it is likely Solas. What he is doing with the orb of whatever was painted at the heart of the slashed Titan, I don't know. It has 8 prongs, though. Eight members of the pantheon if we disclude Fen'Harel. But is eight really so important? Eh. Probably not, as you can read here, haha... we tend to look in to things too much. Like the eight silks across Belle Marche -->
link
Now as for the mural in... was it the shattered library?
This one shows Solas
using the thing in the Titan painting. If the person is still Solas, then on the left looks like a Fen'Harel form. And oh,
bare chested Solas, I might add. There are seven small orb thingies surrounding an eighth, larger one (there's that number eight again). The outside orbs seem to give off energy -- or maybe are symbolic of something (like elves asleep in uthenara). For the large one: it has a ton of eyes not unlike a Nightmare in the Fade -- alternatively, maybe they are representative of something else and it is an overhead view of a crowd of 14 individuals. Mind, we see eyes used a LOT in his murals. So there's probably something... something.
And there is also a pillar of light, which may relate to the weapon mentioned in a story about Andruil (
...She shook the radiance of the stars, divided them into grains of light, then stored them in a shaft of gold.)
And there is a sun burst imagery in the center of that. We know there is a legend about the sun and the earth... but some highlighted texts from various codexes might inform us a bit more:
"...there is a vivid image of green vines growing and enveloping a sphere of fire."
"...an immensely tall, immensely graceful vine that flowers with the heat of a copper sunset and has blossoms as large as ponds, petals as long as a man, and scents puffing out like citron and sky and carrion-death"
"...haloed by a blizzard of light, thousands of elves are maintaining an elaborate magical ritual that pulls raw essence from the Fade, funneled into a sphere in the air."
"...An eclipse as Fen'Harel stirred"
"...We will make the earth blossom with their passing. For one moment there is a vivid image of two overlapping spheres; unknown flowers bloom inside their centers. Then it fades."
Unrelated to the above, but something else regarding codexes: these two may relate to one another:
"...His crime is high treason. He took on a form reserved for the gods and their chosen, and dared to fly in the shape of the divine. The sinner belongs to Dirthamen; he claims he took wings at the urging of Ghilan'nain, and begs protection from Mythal. She does not show him favor, and will let Elgar'nan judge him."
For one moment there is an image of a shifting, shadowy mass with blazing eyes, whose form may be one or many. Then it fades."
and
"For abandoning the People in their time of greatest need, for casting aside form to flee to where the Earth could not reach, we declare Xebenkeck andothers of her ilk exiled from the lands of the Evanuris. Beware! Their familiarity with shape allows them to travel paths unaided. They may be bound, but only the protection of your gods will fully shield you from their malice. They are Forbidden from the Earth that is our right."