Garen's previous sword was destroyed by William, and ever since he learned William's secret sword technique, he had been wondering why Mr. Johnson would use a wooden sword.
It must be that once the secret sword technique is perfected to a certain extent, the material of the sword itself no longer matters.
Also, using a wooden sword probably shows more disdain for the opponent!
Imagine, my opponents used all sorts of divine artifacts and sharp weapons, yet I defeated them all with just a wooden sword.
Who could stand that level of cool?
However, Garen's swordsmanship clearly hadn't reached the level where he could dominate the world with just a wooden sword, especially when facing opponents of the same rank who were so powerful and had such formidable magic. Even with his strong secret sword technique, his weapon just couldn't withstand it.
"Sword, come!"
Garen shouted loudly.