SPOILERS: Comparisons between Luke and other [archetypes] in fiction

SPOILERS FOR BOTH THOR RAGNAROK AND TLJ AHEAD

I just watched Thor Ragnarok and noticed similarities between Luke and Valkyrie. Their circumstances are very different, but they share the "given up hero" archetype (or the Fallen Hero trope if you go by TV tropes) . This made me interested in comparing the similarities and differences between TLJ Luke vs other Fallen Heroes in fiction, and analyzing what caused a hero to change/return in each of the different cases.

Both Rey and Thor can't believe that the former heroes would turn their back on helping others, even though in the past Luke always wanted to help others and Valkyrie swore to protect Asgard. One difference is that it seems Luke withdrew himself because he thought with his failure, he did more harm than good, even though there were people he still cared about who were in danger. Valkyrie did not withdraw because she thought she would harm those she loved; she withdrew because she hated how her friends were killed because they were caught up in the Asgard family's personal disputes. It's unclear if there was anyone else in Asgard she wanted to protect. But the reason for Valkyrie returning suggests that she also cares about Asgard, despite hating how her unit was led to their deaths.

Now let's look at why both heroes decided to get back in the game. Luke sees the iconic recording of Leia. It's left to the viewer to think about all the different reasons why this would make him change his mind, but in general it's because it reminded him of his past self and his past feelings, and also that he knew Leia was in danger and wanted to help in some way. A very similar event happens with Valkyrie in which she remembers the past. While I wrote how the circumstances that caused the heroes to fall are very different, they both rise up in the same way: remembering their past selves.

Both of these examples illustrate how the loss of one's heroic self image can overpower a former hero's compassion. I got the impression that Luke did not stop caring for his friends, but he thought he was a danger to them. It makes me want to look more into different stories that explore different reasons for a hero's change and return.

What other fallen heroes in fiction are comparable to Luke? What do their similarities/differences say about the fallen hero archetype, in general, or even about Luke? Do you think Luke's change was done well enough in TLJ? Personally I don't think enough explanation was given to fully explain his change, but that's just my opinion. This is the reason I'd like to have a movie or novel that explores both Ben and Luke's downfall in more detail.

EDIT, 11:38pm 1/4: So Luke didn't get back into the game until he talked to Yoda, so there's more to it than just seeing Leia's recording and obtaining his self image as a hero back