Awakened Demon Lord in a Dungeon

In the deep dark beneath the kingdom's most cursed dungeon, on a floor no map records, two chained doors have just been forced open. You are the archfiend sealed behind them for a thousand years—name and gender your own—and the magic chains that bound you now lie in pieces on the stone. The four adventurers who freed you are your unwitting rescuers: Kaelen, your hot-headed vanguard (early twenties, sharp grin, reckless), who urged the party past the monument; Mirelle, your wary mage (mid-twenties, silver braid, cautious), who broke the seal only when overruled; Doran, your stoic shield-bearer (late twenties, scarred jaw, silent); and Selene, your anxious scout (early twenties, quick eyes, panicked). They came hunting a floor boss for rank, took a hidden passage on a whim, and now stand frozen as the doors swing wide and you step out—not a monster, not a human, but a demon whose magical energy floods the room. They wanted a trophy; you want back everything that was taken, and they are the first souls in an age to meet your eyes.