
Mordred flaw fully explained and quick analysis of a mirror.
So as far as I can explain it with my understanding.
You need to know that I am believer of Awakened to act accordingly with his flaw and towards it if they are destined to walk path of ascension.
Example: Sunny (connected to mordred) He is unable to tell a lie, therefore by telling truth he gained friends. If he were to decide to keep lying and try to hide things from them they would eventually fade apart, so by admitting everything ro them in Noctis nightmare he gained allies that saved him from solo death.
Anvil instead of loving his enemies and serve out of loyalty to his friends and family he became emotionless sucidial maniac, and died accordingly after losing everything.
Mordred is quite simple, he became shattered and he had to piece himself together by "absorbing" his other selves. It was required because each version of him only experience 1 certain feeling, by becoming whole he is still scattered there are still 7 of him inside and we saw how he acted. Fulldred was switching his emotions every second, ruthless killing, act of mercy, curiousity, friendliness. He is able to express only 1 emotion at a time at 100%, reflecting that emotion against anyone he would face.
If he were to act against his nature he would have experience stagnation, no progress and in his loneliness he would stand alone against stronger and stronger enemies until the last shard broke, died in a pitch afar from anyone that could have saved him. Just as Sunny was dying cut in half during forgotten shore in a ditch.
If he is destined to reach the end he needs to act accordingly to his nature. Existance of a mirror that reflects whats in front of him, how can he help if everything thats in front of him is murderous, vile or want to kill him. However there was something new, a favor, mercy, helping hand with no malicious intentions, she was just there to offer kindness on Kindred by granting memories of his other part, before he was incapable of reflecting that. Now he shall offer to his friends notching but kindness in return.
King of notching, inherited notching but himself, has notching but himself, rules over notching but himself, and like a true mirror he can only offer you nothing but himself and what stands in front of him. Murderous intent for enemies that want to kill him or kindness for his friends.
Here ends my quick and shallow analysis of Character mordred and how similar he is to our Sunny as... well as reflection of him that went the wrong path but found its light in the end, possibly only because Fate was shattered and he was able to choose this destiny for himself just like Changing star was destined to kill Anvil but faced Ki song.