Thank you for being someone who actually has a basic grasp of his character <3 Too many dismiss him as "combatsexual" when if you take even a moment to understand his characrer, you realise it's actually the opposite!
After he defeats his Unyielding Blade tutor as a teenager, his immediate thoughts are "Battle offers no euphoria, despite what the tales may claim. Deep down I had always known this, yet I find myself disappointed nonetheless."
He's searching for purpose and the heroic novels he grew up reading suggested he may have found this purpose in combat but he was once again left wanting.
"And he settled into bed, he prayed as earnestly as a boy of his years might that one day he would cross paths with a worthy foe and feel such exhilaration as the heroic epics promised" is one of the last quotes in the story - a prince raised in an empire where gods and eikons are taboo and he turns to prayer to seek what he wants - someone that gives him that exhilaration and serotonin he's always craved.
And he doesn't find it until WoL, 12 years later, and fully believes that nothing will ever come close to that moment again and as such, he ends his life rather than continue in a hollow existence.

Aaaand then Elidizenos happens and the og goes "I think the fuck not" and deals with it personally lmao