The Many Demon Kings
------
Luminous, the Hero King of the Luminous Kingdom, the one that defeated the Demon King of Miasma in the past, who had to sacrifice himself at the end to seal him away when Erebus had first awakened.
He was a formidably powerful Hero, to go against a monster like Erebus on his own. He was probably someone beyond any level, skill, or player's strength. Singlehandedly capable of fighting a World Boss on his own.
However, it wasn't as if he did this alone, he had many friends, and they gave him their strength. Titania did, and also the Mushroom Brigade, for example.
And even now, Erebus remembers Luminous with fondness, apparently he wants to be like him, which I find rather interesting and a bit adorable, he wants to really be a hero.
"So that's how it is," the Queen nodded. "I did tell you not to speak though!"
"S-Sorry…" Erebus muttered, lowering his head.
"About the Demon Kings…" she said. "Planta, what else did you find out?"