Leviathan was actually not dumb and possessed some brain capacity. He would however often let it be clouded by his emotions. Therefore, he was unable to detect what the Demon Prince truly implied.
"Why? Why?! Because that f****r was a despicable creature that deserves every single retribution that he received! He was always lusting after Flare and tried to put his disgusting paws on her!" The Water Demon screamed out and was so lost in his anger that he forgot completely about maintaining a proper conduct.
"He was pissed over the fact that she loved me and when he finally managed to... to... of course he would want to show off!" He could still remember that day as if it was yesterday.
The talk with his parents in their courtyard about his plans to marry the most beautiful woman in the Four Realms...
The sudden intrusion of the Fire God carrying a body...
The sight of his beloved with only a few torn strands of fabric left over her manhandled body...
The initial shock that soon turned to rage...
The rapist's evil laugh and licking his lips as he bragged about his misdeed...
The delight of hearing the rapist's screams as Leviathan drained different organs of water, but not the heart, so that they looked worse than raisins, before filling them again with their fluids and repeating the process over and over again...
The tremblings of his hands as he pulled her body into his embrace...
The tears that couldn't stop falling as he cried out her name again and again, and wished that everything was just a horrible nightmare...
The despair he felt when her body dissolved into thin air and he tried to grasp even if only a fragment of his love...
The disbelief he was trapped in when his parents softly told him that her soul had already fallen apart...
The attempt to calm him down and find out more about the situation before acting out, which failed badly...
The satisfaction of his slaughter towards the Fire Palace...
The regret and wrath he felt because of the loss of his parents and his clan in the clan war that followed...
He could still recall everything with ease and could still remember every emotion he experienced.
The prince ate another grape before attempting to wake up the Great Water Demon for the last time.
"The Fire High God Flare was the sister of the Fire Clan Head, possessed a cultivation on the level of Purple Fire and was very intelligent. How could possibly a mere Fire God of Blue Fire subdue her? How could he even possibly by himself reach as far as the inner part of the Water Demon Clan's Palace?"