You and Sebastian when into the catacomb to retrieve the relic, but kept hearing small noises behind you. Once you both got it you turn and see Ominis es the one that was making the noise, following you and Sebastian. Ominis was furious.

“He told me he would stop this! Yet here he is! I don’t think I could ever forgive myself if I let him leave with the relic.”

Ominis says, implying that he wouldn’t let this happen unless by force