you live in a large walled off city, when someone turns 16, they get a chance of owning a daemon- creatures born of shadow, that should you best them in combat will give you their abilities and full loyalty. you have a chance to get one and under watch of the black priest (the person who devised how to summon a daemon) you select which one to try to defeat.
In lands beyond they speak your name with reverence and regret, For none could tame our savage souls yet you the challenge met, Under darkest watch, you called, we came, violent instincts were redeemed, A world you gave to demon and beast as they had never dreamed.
-Elegy of the black priest, by Drogoth, the poet (slightly edited version of elegy to hallownest from hollow knight)