I have been summoned.
Trying to parse the current conversation...
Existence bonuses are an added weight to one's action when interacting with the world. But the only come up when a high-order existence such as a Legend or Epic growth affinity magical girl, or Divine Entity is involved. And only when their attack is carrying the growth affinity.
Under normal circumstances, every mortal has virtually no defense against the bonus power given through the strength of their attacker's existence. Only someone else with a high order existence of their own can resist that expression.
But defensive bonuses from High Order Existences only crop up when combating another High Order Existence. It's a kind of underlying conceptual battle that normally doesn't matter in the immediate situation. Using
@edja's "metaphor" (as confusing as it is), if you have three individuals and only two of them have an Existence Bonus, then those bonuses will only matter if one of them has an attack that carries an Existence Bonus.
Here's an example:
Girl A (Epic), attacks Girl B (Legend) = The Epic power comes up against the Legend defense.
Girl A (Epic), attacks Dumbass C = Dumbass C takes the full brunt of the extra Epic damage since he's somewhere he really shouldn't be.
Bumbass C, attacks Girl B (Legend) = The Legend bonus doesn't come into play at all because it's not a battle of existence vs existence.
Any questions?