The true core of the guilty blade, hijacked before the very birth of the sword. It transforms the tool into a weapon that can challenge the intentions of the powers that created it, completing the blade forever. It increases the swords strength, making it able to fulfil its true purpose.
Acquired after returning both of the Fourth Visage's eyes.
Four was the number of the Father’s greatest devotees. Four who witnessed the first miracle. Four who prayed before the young man who twisted and contorted as his joints took root in the towering tree. Four who heard the three words uttered by the Father just before his last breath. Four who admired how the knotted tree, from which liquid gold flowed, grew. Four who were the witnesses to the first Miracle but only one of whom could see the Miracle itself. He saw its form, fate and origin: a divine trinity, the High Wills.
The Apodictic Heart is needed to free Crisanta of the Wrapped Agony from her chains and achieve the third ending of the game.