Black Mist

As Luke received the information that his Affinity had advanced to Mediocre-Peak Grade, he noticed that the black tendrils that were assisting him in increasing his affinity by being absorbed by his core had dramatically shrunk to the point that just one to two tendrils remained.

The two tendrils were absorbed into his Mana Core. Another notification arrived.

[Your Affinity is starting to breakthrough into High Grade]

"Yes! Yes! Yes!" Luke's mind raced as he noticed the hue of his core changing. It was gradually turning a blueish-black tint. The transformation process reached about fifty percent when it abruptly ceased.

[Your Affinity is unable to break through any further because of the lack of ???'s Essence]

As Luke saw the message, he began yelling in his head, "NO! NO! Only a little more. "Please! Please."