Dilan didn't even consider forcing Arnes Cier into submission. He never wanted to have anything to do with his father.
Nonetheless, he could tell that the Primordials would play dirty in order to take back their plaything if something were to happen to it.
Because Dilan didn't know the capabilities of the Primordials, he chose to do something he hated the most.
He activated [Soul Space] to be able to perceive and see his father's soul.
'It looks just like any soul…what did I expect?' Dilan wondered and he sighed deeply when the Soul Space ability was about to make a Soul Imprint on his father to force him into submission.
Dilan held back just before that could happen. Instead of making a Soul Imprint on his father's soul, he used the Soul Space as the replacement for an Eternal Prison. His strengthened soul overwhelmed the soul of Arnes Cier, and tore it out of his Vessel while tying it down deep inside his Soul Space.