Back In the Abyss,
When Zephyr left Zirkos, he finally found Sin's coffin and freed him temporarily, shaking his shoulders to wake him up.
"Sin, wake up, Sin!"
He rose from his hibernating, nightmarish state, blood coating his whole being but the pain had become monotonous for him.
"Huh… you? Aren't you the one who ordered me…?"
"Yes, and.. And I saw, I experienced what you did and I could say is…"
Stopping hesitantly, Zephyr knew what happened at the temple three years ago was unforgettable, he couldn't eradicate the ache he went through briefly.
Summoning Sin shook his whole core and from that he created a certain purpose-
Saving Him
Second main reason for him to enter the Abyss.
"That I am sorry, I am sorry that you had to go through that each second, I am sorry that such horrific thing happened to you,"