He still sees him. Every single day, he sees him. He feels him gently touch his cheek with his pale fingers, he sees him appear in his cell and softly smile at him. He knows he's not here, but he can't stop himself from imagining his touch.
It doesn't matter if he's hallucinating, as long as he can see him. He knows he's well and truly mad, but he wonders if he was ever sane.
He feels himself being pressed up against the cell wall, with the feel of his lips upon his own. He can hear the Lestranges cackling every time he slips into his fantasies.
Every now and then, he finds himself remembering the times they spent together in the Slytherin dormitories and in the deserted corridors of Hogwarts.
He goes berserk every time the Dementors come close to him and he remembers how he found out about his death.
It drives him crazier than he already is, that even though he feels him in his arms, he isn't here.
Barty Crouch Jr. knows that he will never truly see Regulus Black again. It kills him to see him and feel him, but knows that's the only thing which is keeping him alive.