Looking

The Time Prison belongs entirely to the Watcher and is a separate dimension, somewhat reminiscent of a pocket dimension, with a huge "ice castle" stretching infinitely upward. The central area is the largest chamber, from which all floors can be seen at once. Four branches extend from the central chamber, leading to cells containing prisoners and staircases leading to the subsequent floors. The Time Prison is likely a loop. There are no other structures in the prison, including dining halls, because no time means no hunger.
The prisoners and their surroundings are "gray," though it's unclear why. Light penetrates here, meaning it moves and reflects off the surface. Prisoners can move freely around their cells and communicate with each other (through gestures or lip reading). Also, all the above rules don't apply to those who aren't prisoners in the Prison of Time, and for some reason, this doesn't apply to Lucius. Also, as Jodah says, it's become more difficult to move around here since Lucius's escape.
The Prison of Time contains creatures of completely different species and races. Status and power level are irrelevant.

Planeswalkers are beings capable of traveling between worlds using the Organ of Interdimensional Travel (OIT). Planeswalkers originate from the Archean dimension and, thanks to the First Ones, have spread throughout the multiverse.
Planeswalkers cannot be considered a separate species or race, as they can be any intelligent being. They have no distinguishing features other than the presence of a special "organ," the WMD, better known as the "Spark." Thanks to this, planeswalkers possess the ability to "walk through worlds," as their name suggests.

On average, planeswalkers make up 0.4% of all sentient beings in existence.[1] Their prevalence is limited not to just one world, but to entire realities. In other universes, they are not particularly distinct from one another, but, for example, in the JDH's home reality, the WMD is called a "Flash" rather than a "Spark," although the basic name remains.

Not everyone loves and favors planeswalkers, and some even openly hate and despise them. Due to the Spark's vastly superior power and the variability of its appearance, not all planeswalkers utilize it for good. As a result, all realities have gradually evolved into various concepts of prisons designed specifically for planeswalkers.

Capabilities
Change of appearance;
Resizing;
Creation of doubles;
Levitation;
Is a concept of death and time;
Spread of cold;
Erasing objects;
Breaking the fourth wall
Omnipresence: being time itself, it is simultaneously everywhere, at all points in space and time, with the exception of the timeless space of the synclitus.
Omniscience: Being omnipresent, it simultaneously views the past, future and present of everything in the universe.
Psychological pressure: he exerts a chilling influence on others, and his presence causes intense fear and paralyzing anxiety in the unprepared, as well as a feeling of a "raised sword"; in addition, he makes various noises and whispers, and is constantly shrouded in a dark "smoke."
Paralysis imposition;

He is a god or the personification of time.
There's always a chill about him.
Can communicate with glances, for example: "The icy gaze of the viewer expresses nothing."
He can consume food, but it is neither hot nor cold, although he feels the taste.
There's a time prison, where dangerous criminals are imprisoned for eternity, where they turn gray. The prison itself has white walls and seems endless (but this isn't true, as the overseer has a living space at the very top, containing his quarters, a kitchen, and other rooms).

loves his daughter Emily more than anything in the world

The Watcher wears a dark cloak with white buttons, the cuffs of his sleeves are made of soft white fur, and a hood with the same fur is thrown over his head.
he could only speak in the wasteland (timeless wasteland), for countless years
2 meters tall, black hair down to the chin, hidden by a hood, coal-black skin, elven ears, white eyes, slightly glowing and without pupils, a mouth, white and sharp teeth, a long and black tongue, short but very sharp nails (or claws) on the hands, also the viewer could summon tentacles (they could appear either from the floor or from the back when he wanted to show them), he felt when they were touched, the body is slender and with a press.

the voice is low, cold... no, rather with an icy echo, or maybe with steel