After Adrian rested and his health got normally regenerate since Aurgelmir stated that potions did not regenerate blood, he started connecting to the Nether Realm. He needs to actually tap into the nether energy first so that he could connect the portal he is creating to the Nether Realm.
Adrian's body started to somewhat transform to become like nether mist. His eyes started to darken as he started to channel the dimensional energy needed to open a gate to the Nether Realm. Adrian once again used the Cube of Paradox as a conduit in order for the spell to work without much hassle.
The Cube of Paradox broke into tiny pieces that are smaller cubes and radiated spatial energy. The entrance that Adrian made is similar to just a mist. It looked like a cloud that had the same colors as the nether mist is summoned in front of him with the smaller cubes outlining it.