Character counterparts... How are you interpreting it?

Not debating this theory itself but assuming that venin are some kind of power balance or character counterpart

What kind of counterpart are we thinking?? Like is it

- 1-1 counterpart (each person has a venin counterpart)

- more symbolic?

- personality/traits

- future predictions or downfall kind of parallel?

Because depending on how you interpret it, it's either just a fun story element or has a much larger impact on the future story? Like depending on how you interpret it I think it shapes what you think about character decisions and the honestly, the entire narrative!