1. Who would sell their soul to the devil to save the other.
2. Who would become a stalker, in the right (wrong) situation.
Yuya bc he’s already chasing her across dimensions, just got to add in some Zarc maliciousness
3. Who would pine away in silence their entire lives without confessing their love.
Yuzu bc feelings are stupid and embarrassing and she has to be 100% sure to make the first move
4. Who would leave their friends, family, and life to move overseas to be with the other one.
5. Who would be the most worried the other might cheat on them.
Neither it just isn’t a concern
6. Who would run into a burning building to save a stranger while the other calls 911.
7. Who would haunt the other after death and chase away other suitors.
Yuya (although once he got settled down then he would chill on the chase away part)
8. Who would stand up at the other’s wedding and say they object.
Yuzu, bc once she has any idea that there are feelings there and sees that point of no return approaching, she would definitely fight for her man
9. Who would write long, beautiful poems for the other.
Yuzu tried once, but neither are that literary
10. Who would love the other no matter how evil the other became.
Both, Yuya in a more enabling way, Yuzu in a more “I will fight you to save you” way
11. Who would be the most likely to become an addict (gambling/drugs/etc.).
12. Who would propose in a grand gesture of some kind.
Yuya bc he is nothing if he isn’t an entertainer at his core
13. Who would go berserk at harm or death befalling the other.
Yuya, this is pretty much canon
14. Who would spend too much money on expensive gifts for the other.
Yuzu, it is a way to make up for her initial shyness
15. Who would fight an impossible battle to give the other time to escape.
Both, Yuya is more likely to do so bc as caring as she is, Yuzu also has strong self-preservation instincts
16. Who would be able to spend centuries in misery waiting for the other to be reborn.