About crossovers

[Avengershows]

So about crossover scaling. Let's say that a crossover canonically happens in one series, but not the other, how would scaling work?
Example:
Character A goes to Franchise B, in said franchise B, the story takes place in another universe that is related to the main universe but doesnt affect it, and lets say that Character A has H6C feats in their own franchise and is completely in character, doesnt have any irregularities.
How would the scaling be treated?

 

[QuasiYuri]

This

 

[Avengershows]

This

I read it already and the explanation is still very confusing.