He's forced to relive the deaths of his family at his own hands over and over.
Maybe you've heard that purgatory is reliving your worst memories over and over and you can't escape it. And here is exactly where Gerard was. He was in purgatory. Even though in life he never believed, in death he was forced into it. He was forced to relive the worst few hours of his life over and over again, unable to do anything as his body went through the motions like a puppet on a string, not even scream.
Just when he though it was finished,, it began again. His family, his wife and kid, brother and parents were at his house, as well as Frank with his own wife and kids in tow. Gerard saw it all so clearly his heat began to ache yet again. No, there has to be some way to stop this! Not again!
But it continued. His body moved of its own accord, going into his kitchen and grabbing the biggest knife he could find while in his mind he screamed no. He herded them all into the basement, while they asked what the hell was going on, why was he doing this?
His father stabbed through the heart.
It started again.
His mother's intestine's ripped out.
Mikey's arms sliced along the vein, wrist to elbow.
His own screams echoing in his head.
Lyn-Z's throat cut.
He would've cried if he could, but he couldn't even manage that.
Frank's throat ripped out, leaving him to gurgle on his own blood.
There went his best friend.
Jamia's neck broken.
Just stop it!
Bandit's brains smashed out against the cruel concrete wall.
Not the kids!
Miles' baby head completely torn off.
It went on.
Cherry and Lily stuffed into the furnace which he then turned on.
Oh God, what've I done?
His heart was hurting to the point that if he were still alive he would've already died of pain. Only the worst people deserved this. Even though he;d killed everyone who mattered to him, he'd do it all again just for some Novocaine to end the pain.