The kick by Alex was just a test to measure the strength of Kain. He knew that Kain was strengthened by mutant cells, so the quickest way for him to test that was by attacking first.
With just a kick, Alex accurately grasped the level of physical strength of Kain.
And it was within his expectation.
Kain was as strong as a tier 4 warrior physically. But, Alex didn't feel threatened by it. After all, he had the same level of physical strength.
However, it didn't mean that Kain was easy to defeat.
Kain was a master-level mage before he became physically stronger. So, the threat of magic still exists.
'When comparing skills, I am not good enough to be a master mage. And I don't have that much experience in physical battles. Usually, I win against my enemies by overwhelming them by using teleport and by using unpredictable mana attacks.'