Since embarking on the path toward Tyrant Fist, doesn't that mean defeating all the top fighters of his generation? Whale King Arlington from the Yana United States' Martial Arts World, Magic Phoenix Saint Fist, the current leader of the Door Organization. Casio would let anyone who appeared before him experience his cultivation and see who was superior.
Moreover, Casio even hoped that these two would appear before him at the same time. He always felt that his own strength, having pushed his Qi to the realm of an Ultimate Fighter, and reaching the extreme level in all three aspects, was terrifyingly strong! If he faced only an Ultimate Fighter, it would hardly bring any unexpected surprises, and it might even leave Casio feeling unsatisfied.
The significance of sparring is minimal if his full strength can't be forced out.