What do you think was the purpose of Damon appearing to Bonnie when she first entered his mind but then he turned into Tyler?
She used the locator spell with Grams to find Damon, so it took her to the cemetery/crypt where we know he was because that’s where Stefan found him later. But remember Damon was hiding in there, “dead”… his subconscious was trying to force a world into existence where he didn’t exist, but here’s Bonnie, seeking him out.
So I think his subconscious took on the form of Tyler, the person whose death supposedly no one was going to forgive him for. But, and not for the first time, Bonnie will surprise him by seeing through him.
Because she’s seen this song and dance before. Back at the Grill, Caroline is confused by the fact that Damon’s subconscious would create this world where all of the sources of his guilt like Vicki are there to haunt him, indefinitely. But Bonnie saw him in 1994, making those pancakes every. single. morning.
She knows that once again this is the evidence of his remorse, his infant attempts at repentance. And as always, she reminds him that that remorse means there’s hope for him. She tells “Tyler” that Damon may spend the rest of his life atoning for the things he’s done, but she believes he can do it. And that she knows it’s scary, but he just needs to believe he can do it too.
And that’s exactly what Damon needs to hear in that moment (note how he tells Stefan later that he doesn’t need Stefan’s forgiveness, “Bonnie helped me work through my issues”). All that he needs after that is to square away the loose ends with his brother, ie. the resentment that he still clings to after all these years. He still blames his brother for the monster he became, and that’s a part of why he so often has found himself powerless to change that monstrosity he sees within himself.
Bonnie immediately senses that as well in the crypt, snapping herself out of the trance to get Stefan there to make that happen.
No other two characters on this show understand each other through and through the way Bonnie and Damon do, to the point where it’s nearly instinct. Endgame or not, that is theirs/ours.