What Happened To Every Version Of The Hulk?

The scariest of all the collected Hulks, the Guilt Hulk is a manifestation of Banner's memories of his father, combined with the guilt he feels about the damage the Hulk has caused over the years.

Bruce is forced to confront this version of the Hulk when attempting to create Professor Hulk, which sees him and Doc Samson go deep into Banner's psyche. When all of the scientist's memories of his father are replaced with a nightmarish hellbeast, Bruce begins to recognise that his deep-rooted trauma was likely the cause of the creature, and is able to defeat it by recognising the turmoil his abusive father created in his life.

While the Guilt Hulk was supposed to also have been retconned out of existence by Peter David, he has appeared since then in events like Chaos War, so it looks like he's still canon.