Chapter 123- The Elite Four

Zach's fighting style had five options depending on the opponent he was fighting.

His first option was to fight back. His second option was to dodge. His third option was to block. His fourth option was to absorb opponents' magical attacks. And his fifth option was to do nothing.

Zach had realized that dodging attacks wouldn't work, so he chose the fourth option.

The third option was to block the attacks, but it was a useless strategy against Maxim since he was predicting Zach's move.

The fourth option was to absorb Maxim's lightning attacks and tire him up before beating him unconscious.

Zach couldn't use the fifth option because it was stupid.

Of course, Zach would have used the first option and killed Maxim if he wanted to. But he thought the sixth would get in trouble. 

Sure Zach didn't care much about the sixth, but he was worried about Aquarius and the kingdom, who could get into a mess because of Zach's actions.