I have a particular hard on for Tezumak. He's monstrous in our eyes because his faith dictates certain gruesome sacrifices. But as we saw (or didn't see in the fight at the theme park) he bends the rules only as far he can without taking innocent life.
To get the blood to fuel his armor for his 2nd clash with the League, he took blood from the children on the roller coaster, but nothing more than a what you would when drawing blood at a hospital for testing. nothing more. With enough kids, the amount he drew was enough to appease his gods and fuel the battle armor.
As for the mutiliation, he mutilated himself so that others would not be hurt, per his traditions.
With that piece of the armor still at the JLA station, I hope that it makes it's way back to Latin America and we see a new Tezumak.