If my main character gets powerful for each emotional trauma,How do i describe it?

Question

My main character gets more strength for each emotional trauma he face it,But his mind gets massive damage for each trauma,How do i describe it? What should i write when he becomes a madman necromancer? Lets say his twin soul betrayed him,Now he is just a killing machine craving for revenge,His main goal is to claim his twin soul,Alive or dead.

My main character traits :

He was a poor hybrid kid living in a xenobophic elven kingdom,He was a slave and somehow the princess of said kingdom got in love with him (A love chemical/fruit),The family and people of this kid,And his precious pet were killed by religious xenophobic royal guards,When the effects of that love fruit ended,She broke his heart,He didnt gave the potion to her,It was the fault of destiny,They were starving and ate the love fruit,Sadly said fruit had limited effects,Like a powerful aphrodisiac,both characters were trapped in an island with nothing else to eat.

Answer 1

Okay, with the information that I have gathered, he's fragile, the love of his life broke him and his kind is being slaughtered. He sounds like he's got it rough. You said that you wanted to describe his mental trauma like scars. Think of it like this; Have you ever had a headache so bad that you could hardly talk? Have you ever had a fever so bad that you're sweating profusely even though you're freezing? Have you ever been hit in the head with a ball? (by accident while playing a sport or just being in the way at the wrong time).

Imagine all that pain and put it into words.

"My head throbbed as if a thousand tiny feet were kicking my skull from the inside, sweat ran down my forehead in rivulets and the heat - oh the heat. It felt as though I was running a marathon in the scorching desert, it was humid and I could hardly breathe."

Description is key. The more you add, the more of an image you create. I hope this helps!