Klaus spent four full days in the training room, pushing his mental limits. Even though he had the Weapon Overlord Class, which allowed him to control weapons with his mind, it didn't mean he had perfect control without effort. It only gave him easier control compared to most, but he still had to work hard.
His mental strength was crucial if he wanted to keep the needles flying for a long time. Of course, he didn't let this challenge hold him back. Instead of settling for controlling just 33 needles and a single attack pattern, he pushed further. Now, after four days, he could effortlessly control 54 needles without much strain and had even mastered three more attack patterns from the [Ten Thousand Soul Needles] technique.
Along with the [Void Piercing Needle], which allowed him to combine 54 needles into one long, 14-inches needle for a powerful strike, he had also mastered three new techniques: [Swarm Attack], [Infinity Piercing], and [Jagged Strike].
