Marcus Brutus, the 7th Hero of Nature revealed the grave sin he committed in the past just to past the trial set by the God of Nature for him inside Babylon to enter the God's Altar.
And the way he achieved that even left Kahn perplexed.
"God of Nature was furious with me after seeing how I handled things.
He said that I did not deserve to be a chosen Hero and he could never trust the fate of the world with someone like me who would even sacrifice his closest people, who fought with me even at death's door; instead of fighting against the chains of fate." said Brutus and revealed the consequences of his choices.
"That day…
God of Nature cursed me and the remaining of my party members to be stuck here inside Babylon.
And the only way to leave would be to kill another Hero or Heroine of Nature and offer their core as the sacrifice at God's Altar to leave Babylon." revealed Brutus helplessly, his face still carrying the shame of his past decisions.