After surviving the second Tribulation of Hell, one of the rewards he got was the skill called Eyes of Truth and Judgment.
When Corey obtained the skill, he barely knew anything about the skill. He had rudimentary information on the abilities of the Eyes of Truth and Judgment.
When he first got the Eyes of Truth and Judgement, he learnt that most of its abilities were somewhat similar to his Eyes of Omniscience and even his Tri-Pupil Eyes.
He could see glimpses of the future with it, the weaknesses of anything, see through deceptions, and also know the best possible outcome for his actions.
His Eyes of Truth and Judgment could do all of these, and it could also allow him to see the True Path.
Corey had no idea what the True Path meant in the past and even now, he was not fully certain about its meaning.