How does Narcissism work exactly? Double defense or half Attack Power?

[mcf]

Hello there,
 

I've been wondering how Narcissism in both champion battles and PvP battles work. As far as i know, whenever "Narcissism"  occurs it should give your girl double the defense. However, when it activates in a champion battle, my girls manage to gain 50% of my Attack Power as additional defense. For example, if i had an Attack Power of 30000, narcissism gave me 15000 ADDITIONAL defense (so on top of my current defense). This happened during Champion battles, but I have not gotten the opportunity to try this out in seasons/leagues (I am a KH user). Whenever "Reassurance"  happens for example, i gain 10% of my total Ego. Am i missing something, or is this the right calculation? See the pictures below for some references:
 

 

During this round, Narcissism was active and gave me an exact 50% of my current Attack power as additional defense. Also, you can see that this is the final stage of the champion battle (meaning we both have 0 defense against eachother), yet i manage to gain 16283 defense (50% of my Attack power exactly).

Edited June 24, 2021 by mcf