Answer:
Based on his age, and the description it can be concluded that he represents the stage of early adulthood.
Step-by-step explanation:
According to Erikson's stages, early adulthood representes the time when the virtue developed is love, with the conflict been that of intimacy against isolation. This can be seen in Devin's case in the fact that he is struggling to develop a healthy relationship, and that he has not been able to keep long-term relationships.