[Fantasy + alternate world + no System + serious + not mindless + ensemble cast]
The Untethered Realm series
In this world, power has a clearly marked price. Stardust crystals let you wield arcane force, but the cost is your lifespan. Every time you grow stronger, you burn away the life you have left.
Eleanor, a pureblood girl who clawed her way out of a scrap heap, is chosen by a crown that devours the life of its wearer. The world calls her the Demon King, but she wants only one thing: to find a way for civilization to endure without burning through people's lives.
And a man bearing the name of a dead companion is already waiting for her at the end of that road.
