Capítulo 249: Old Man In Golden Attire

The reason it was important was the Skill Documentation Use of the book. Besides, Queen Retina was sweet enough to turn the different methods he had used Arf before into a valid Skill and document them in it.

For example, Seth has used Arf to make red strings around him for protection, he used Arf to encase himself in a cocoon and trap dragons in them, he made a whip that attacks and defends him, and he also used it as a cushion to reduce impact, he also trapped Zambia group in a foam-like prison.

Arf was very valuable and even though he has a lot of it, it will be a waste to be using it in this trivial matter. As such, the Skill Documentation has a recipe, process and techniques to create different sets of red liquid that can be manipulated to produce a set of Skills. 

That means he needs Fusiom&Fission a lot.