The improvements done to the Abyssal Needle weren't enough to bring it to the third Rank.
There were several reasons for this.
One, Liam couldn't make something so intricate with Rank 4 materials.
Without a stronger core, manipulating, purifying and shaping Rank 4 materials was extremely difficult.
It had taken Liam 4 months to make the Dusk Blades, after all.
And even then, he had to center it around the Rhino tusk and horn's curved shape.
Meanwhile, the Abyssal Needle consisted of complicated, small-sized parts.
It was no wonder Liam had to resort to weaker materials.
Secondly, the Abyssal Needle was a fairly new item.
The only reason Liam could make the Rank 3 Dusk Blades was because he had years of experience working with blades, daggers and swords.
And thirdly, Liam hadn't advanced to the solid stage yet.
There was just so much work!
