This is Tigerstar thinking, and the "they" he refers to is Starclan, and "you" is Firestar. Based off of Echoplex, by Nine Inch Nails.
Nice and high, and far apart
Just like they said
Tigerstar was pacing back and forth in the dark forest.
The trees were ominous and with dark spaces in between.
I built this place with broken parts
Just like they said
He thought of all the broken hearts and bodies he caused to get there
You chip away the old version of you
You'd be surprised what you can do
When he discovered what he could do in the dark forest, he felt like a new cat.
I'm safe in here
Irrelevant
Just like they said
He ruffles with rage when he thinks of Starclan, that put him here to be
out of harms way.
My voice just echoes off these walls
Thr crushing loneliness would be too much to bear for other cats.
You feel my eyes, I am watching you
I see it all
He walks to the edge of a pool, where he watches Firestar living his life normally,
every once in a while almost catching him.
Many ways you can't get to me
I see it all
He knows that Firestar is not convinced that he is gone, but he feels safe.
I see the hell I have put you through
The shell of a cat, Bluestar was the way she was because of him.
Oh the things I could do if I wanted to
Training his army of living cats, he imagines them in battle.
My voice just echoes off these walls
I don't need anything at all
He feels invincible because he never feels hungry for anything accept revenge.
My voice just echoes off these walls
And I just slowly fade away
He watches as the clans resume their normal lives, as he becomes an elder's tale.
You will never get to me in here.