The Master stared blankly at the remains of Gallifrey from the door of the TARDIS he had stolen to escape in. There was nothing left but floating debris and the dark ash coating his skin. He closed his eyes and spread his arms wide, determined to enjoy the remains of his endeavor, but still, he felt no relief. If anything, his rage and the pounding in his head had intensified. BOOM-BOOM-BOOM-BOOM, BOOM-BOOM-BOOM-BOOM. Even after the actual drumming had ceased, he had found that the memory remained, haunting him in place of it. In the stillness, it worsened.
He had somewhat come to terms with his fate, and then he had found that cursed matrix of forbidden knowledge. Naturally, his desire for the power had driven him to break in and learn of Gallifrey's dark beginning. He was happy to have leverage over the Doctor, but the knowledge that he was nothing but another product of her infuriating abilities. She would live forever, even after he inevitably perished, running around the universe and reveling in her superiority. So much for attaining immortality. Would she miss him? Probably not.
No matter how brilliantly he schemed, he could never break her. She would always rise up to save the day, against all odds. He didn't know what he hated more, watching her act as though she were better than she was, or seeing her comply with his demands, determined to sacrifice her life and her pride to save a bunch of random humans. He sighed frustratedly, opening his eyes to stare into the distance, searching for he knew not what. He was not out of options, but getting a bit too close. He wanted to make her gaze at him in shock and awe at the grandeur of his greatness, knowing that he had inevitably attained ultimate power with a level of genius completely his own. To make her understand that he didn't need her at all. That he wasn't simply another adoring human, eager to gawk at her ridiculous little party tricks.
He wondered where she was by now. Was she safe in her own TARDIS, celebrating with her stupid "fam" and reminiscing over their triumphs? Did she think him dead? Or did she understand that no matter what she did, no matter how hard she tried to defeat him and stop him for good, he would never give up. He would never rest, not for a single second, not for a single moment….
He gasped, pressing his hands to either side of his head, struggling to regain his composure. The booming in his head was returning once more and with full force. She should not have this power over him. He shouldn't need her attention to feel accepted, to feel something so trivial as love. And yet, he did. Some small part of him was the same child who ran with her on the plains of Gallifrey all those years ago. But only a small part. This ridiculous moment of weakness would pass. He had survived yet again, he always would, and one day, he would have everything he desired. The Doctor may feel safe for now, but she wouldn't be. Not for very long, anyway.