I am going to answer this question by comparing Jackson from Alexie's excellent story and Daru from "The Guest." I have included links below that should give you more information about Sherman Alexie and then the other characters in "The Guest" to help you further your analysis.
Daru is an isolated individual who is somewhat monastic in the way that he chooses to live apart from his setting. A schoolmaster of a rural school, he is shown to be extremely compassionate and empathetic with the locals and the way he treats the Arab. However, in spite of this basic human decency, he finds himself greatly irritated by the prisoner's inability to assert himself and the transgression that he committed. Daru does his best to frustrate official orders to transfer the prisoner, but his actions are misinterpreted by everybody at every turn. Although he longs to be a good person, he is shown to not be able to be "good" in everybody's eyes, and thus he ends up even more isolated because he is hated by the locals and the Arab's compatriates.
In "What You Pawn I Will Redeem," Jackson is likewise shown to be an outcast thanks to his ethnicity and his inability to lead a "normal" life. As an Indian, he has chosen to adopt a lifestyle that leads to his shunning from "normal" society on the whole. The challenge Jackson is given to get back his grandmother's regalia allows the author to present him and the various people that he meets in the full bleakness of their position. Again and again, throughout the story, Alexie points out the fate of indigenous people through the rumours that Jackson hears of the people that he meets. Thus it is that the sad fate of Rose of Sharon and Junior are eluded to briefly in the form of a rumour. Jackson is a character who presents himself as human and demands that Indians be treated like humans as well:
Probably none of this interests you. Homeless Indians are everywhere in Seattle. We’re common and boring, and you walk right on by us, with maybe a look of anger or disgust or even sadness at the terrible fate of the noble savage. But we have dreams and families.
Although he is isolated from society, and that does not change at all, Jackson's ability to save $5 impresses the pawnshop owner so much that he gives Jackson back his grandmother's regalia so that he is able to maintain his cultural identity.
Both characters are therefore good people at heart, although the way they try to express that goodness is often questionable. Most importantly however, both characters are social outcasts and misfits, and are even more so by the end of the story.