Other fun thought I remembered to discuss. I like how Rex looks up to and idealised most of the adults around him and takes part of them into his sense of self. Corinne likely impacted his cheerful and helpful personality, as he wanted to become like her and help those around him.
The second most important person in his life is definitely Azurda (or Gramps, as he likes to call him). Azurda becomes his parental figure alongside Corinne, and Rex wants to become a man who can pay back the ones he loved who helped me grow into the kind of person he currently is.
Rex misses his parents, even if he never knew them. He knows they wouldn't want him to be wallowing in his own sorrow and it's why he focuses on trying to become someone others can look up to. He struggles to show weakness, as he feels like it's disrespecting those who sacrificed themselves for him.
This is why Vandham's death, another man he looked up to as a parental figure. Affected him so hard. Rex spent most of his life being someone whose loved ones died to protect him. He feels that unless he becomes someone who can silently suffer and help those around him; they died in vain.
Rex, even post Xenoblade 2, took a lot of himself based on Vandham especially. Despite the short time he knew him, Vandham impacted him strongly, and he wants to respect the man who died to protect him and his dream of Elysium.
Morag and Zeke also became older figures who shaped Rex into the man he later became. Rex is a person who loves to please those around him, even at the cost of himself. It's due to this he struggles with his own self perception and had to shape himself through his experiences with the others he met.
Rex's fighting style and clothing sense is inspired by both Zeke and Morag by the time of Xenoblade Chronicles 3 also. He looks up to them both and takes their power into his own. It depicts how much his allies play into Rex's strength and the way he inspires those who come to idealise him also.
It's due to this that Rex, as he is during Xenoblade 3 is like an ultimate representation of a man who lives not for himself but for others. It's both tragic but also realistic that he still has self image issues from his experiences.
Despite that, Rex became a man who could help others and does inspire everyone around him. He even saved Malos and Jin at the end of their lives by opening their eyes to what they had and the good they achieved during their lives. I love this man so much.