Oh, Gallifrey was a bright world. He can't bring himself to call it cruel. Maybe by human standards it was, bringing eight year olds up away from their parents and making them learn things like Advanced Time-Space Manipulation and Multi-String Physics and The Historical Eras of the Slitheen. A lot of the kids worked hard and studied and sniffled the first few nights at the Academy. The Master can't remember ever crying, but he powerfully missed his mother telling him stories of his ancestors and past civilizations and Toclafane.
Human standards didn't really apply, though, when talking about the majestic, aloof dominion of the Time Lords. It was with human ingenuity and human guts and human standards that the citizens of Utopia gave their homeworld to war and to the Master for a year.
(All ruined by one girl, one little girl walking to and fro on the earth like a lion, while her mentor withered in a bird cage-)
But that whole war was by human standards, using human metal and media and their absolutely fantastic, rollicking music. It was a show, but the goal was greater, so great, Gallifrey-bright greatness-
In the grand tradition of the Time Lords, each child went alone to the keepers of the void, and then the keepers would step back. The child would look into the abyss alone. It was amazing that the Time Lords had captured the abyss at all. They had put clamps around the universe itself and pulled it apart like a wound, but this was gentle doctoring. The universe permitted them because bleeding it kept it healthy. The void was what every thing, eventually, came down to.
The Master, at the age of eight, shuffled nervously up to the void with his hands in his pockets. Other kids had done this. They all had, in fact. He could do it too.
The not-quite-Master-yet took his hands out of his pockets. The keeper of the void and his petal-shaped hat stepped backwards.
The not-quite-Master-yet looked.
He saw the universe from beginning to end. First, it was mostly colors: deep blue, bright white, the most honest magenta seen anywhere in the galaxies. He saw time chug into motion like a cold, sluggish engine. He saw the end.
The end of the universe was not particularly violent or, for that matter, particularly devastating. There wasn't much left to devastate. It was the reverse of a slow burn. It wasn't even a desperate ship full of humans reaching Utopia.
The end of the universe was a little creature crawling out of the evolutionary ooze, blinking at the stars, thinking its first thought*, and quietly expiring in the noxious air.
The Master had never heard of the human expression 'when you stare into the abyss, the abyss stares back', but it stared back.
Inside his ears and so loud into his thoughts that he was certain he could project it, the drumming started.
Years later he could never say what made the sound inside the void. There had been eyes, but nothing else. So what really scared him was the question- what was it drumming with?
He stared and stared, trying to find out, and kept staring for the rest of his life.
* "Would you look at that!"