Cían (ReedSun timeline): he struggles for quite some time with internalized self-flagellation, blaming himself for so much of the tragedy that is completely out of his hands. it takes a lot of time for him to move on past this, especially when he has a particularly bad setback involving the death of one of his friends.

Musician (HoshiSun timeline): he has a bit of an issue feeling like he'll never amount to the example set by his prestigious and outstanding parents, though he chooses to work through this by focusing on furthering his career in music + training hard every day to be an exemplary Defender Operator at Rhodes Island. (fun fact: Musician Isa starts his music career far earlier than any of his other timelines)

Composer (KalSun timeline): much like dear old mom and his dad's old bad habits, he has a problem of letting his work and responsibilities take complete control of him. ultimately it takes his friends and family to get him to properly balance his work and his personal time and while he may not show it so easily in this timeline, he still cherishes and appreciates the efforts of his loved ones despite his insistence on burying himself in work out of self-assigned "duty".