This story wouldn't let me sleep until it was written. A few lines are pulled directly from the game.
Solas started down at the remains of the shattered sphere, never having predicted this outcome. Giving the sphere to Corypheus had seemed like the logical choice at the time in Solas' weakened state, too drained after his long sleep to unlock it on his own. He certainly hadn't expected the lengths the magister would go to unleash its power, the destruction and chaos that he would cause. Solas had thought he'd have time to regain his strength, to take it back when he was able, well before Corypheus was able to harness its power. How wrong he had been.
Pride was always his burden, Solas more title than name, thinking himself so capable. He watched his friends rejoice after Corypheus' defeat (mortal friends—the concept was so foreign, though he was unsure if he had the right to call them friends after his long betrayal, what they would think of him if they knew the truth, what he was, what he'd done, what he still had yet to do). His eyes were drawn to the Inquisitor, Mahanon Lavellan, his friend and a kindred spirit, an elf who respected the past, but did not live by it, did not let it shape him… entirely…
Eyes drawn to Mahanon's vallaslin, Solas' lips curled in distaste. Far too often, the words had been on the tip of his tongue, the truth behind their origins, but he could bring himself to add to his friend's despair.
Mahanon turned towards him, a wide smile across his face, the weight of the world at least temporarily lifted from his shoulders, making him look so very young and making Solas feel so very old. Mahanon smile was welcoming, questioning, come join us, my friend his eyes said. Perhaps… no, not in this lifetime, nor in any of Solas' lifetimes. Such things were not for him.
As Mahanon was drawn into conversation, his eyes were pulled from Solas, and Solas used the opportunity to slip away. When Mahanon looked back, Solas was gone. It was the coward's way out he knew, but he had much to atone for, much to make right before he could return to the path long set before him. Leliana and her network of spies would search, but they would find no trace of him, unable to walk the paths that he could access.
Still weak from the battle with Corypheus, slipping to the place between worlds drained Solas more than it should have. Such a task used to be effortless, the cost nothing in the face of the well of his power, and now he was reduced to this. Pathetic, he chided himself, what he had fallen to, what he had become.
Even with all the damage that Corypheus was able to do, he'd been unable to unlock the true power of the foci, had barely done more than scratch the surface of its secrets. If Mahanon hadn't interfered, if he hadn't become—Solas cut off that train of thought. His orb was gone, but its power…
An unexpected presence ripped Solas from his thoughts, but he realized it was where his feet had been leading him all along, back to the familiar in the search for some small comfort in the one place he might find it. Flemeth nee Mythal, once named the wisest of all the People, turned upon by friends, betrayed by those who thought themselves better, who thought themselves right, by those who grew jealous of her power, power they would never have.
"I knew you would come," Mythal said, turning to face him, face etched with sorrow. "You should not have given your orb to Corypheus, Dead Wolf."
"I was too weak to unlock it after my slumber. The failure was mine. I should pay the price, but the People, they need me." Solas leaned into her touch, allowing himself a moment of comfort. "I'm so sorry." Please forgive me for what I what must do. I have no other choice.
"I am sorry as well, old friend."
She knew, of course, she knew, Solas realized, her eyes going wide as he pulled from her, the trickle giving away to a flood as the dam fell away, the power rushed through him, into him. Mythal gave everything, holding nothing back, and Solas gorged himself, full to overflowing and then some. Carefully, reverently, he lowered her body to the ground.
Raising his head, he took a shuddering breath, forcing the power to settle, letting it soak into him, claiming it as his own. But there was something strange there, something—an Old God's soul—how did she!? No, it did not matter now. "Thank you, my friend," Solas whispered as he rose and left without a backwards glance.
There was much to be done.
Solas could feel Cole searching, wanting to bring comfort to himself, to Mahanon, to ease his burden. As much as Solas wished it, he could no allow it. "I'm sorry Cole. I fear that with your gift you might see the path that I must now walk in solitude forever. This fate in mine alone. Indeed, I would not wish it on an enemy, much less someone that I once cared for. Though you reach out in compassion, I must insist that you forget."
For one brief moment, Solas gave into his selfish desire and let himself view Mahanon through Cole's eyes, taking in the confusion then the startled look as he realized whose voice was flowing from Cole's lips.
"Solas, please come back."
Wrenching himself away, Solas raised a hand, startled at the tears wetting his cheeks. He could not remember the last time he cried. He could not go back, could not afford the distractions, the temptations. This was a path that he could not stray from, not after all that he'd given, all that he'd done. Already, he had strayed too far, but the events at the conclave, the creation of the Breach, had given him no choice. And what he found in a Dalish elf threatened to topple it all.
Corypheus called it an anchor with what little knowledge and understanding he had of it. It was fitting enough a name in a twisted sense, for what was an anchor if not something that offered support and strength, tethered to something greater? If Mahanon knew what he was marked as… Solas could scarcely bear the thought. After everything he'd strived for, everything he'd sacrificed, his action and subsequent inaction had brought about the very thing that he reviled.
Mahanon was marked as his slave.
Solas could have done nothing, could have let it consume Mahanon unclaimed, could have taken it upon himself, but his pride would not let him. Too many innocent lives had been lost because of him, and in that moment, seeing Mahanon wracked by the pain of Solas' indecision, he couldn't do it, couldn't sit idle and watch Mahanon die. Instead, Solas had taken Mahanon in hand, accepted his unwitting offering, guided the power, his power, showed him how to use it. And in doing so, Solas had damned himself.
More than Mahanon's reaction to who he was, to what he was, Solas ran because he could not burden Mahanon with the truth of what he was. Or so was one of the many lie Solas said to placate himself, for they were easier to accept than the truth: that he had fallen in love.
Such emotions were weakness, unnecessary distractions. Solas had become soft. It was time to cast off such trapping and embrace what he was: Fen'Harel, the Dread Wolf. Flemeth's machinations were nothing compared to the events that he would set in motion. The time for change for upon them.
This story is brought on by me thinking way too much about what happened at the end of the game, what was revealed, and the many, MANY questions that went unanswered (and me not having anyone to talk to about it because none of my friend have finished the game). As this wasn't supposed to have a happy ending, I do plan on eventually writing more in this universe.