Too Human

This Achievement is unlocked when you assign your first Skill Point to a Battle Cry node on the skill tree. This assigns a battle cry ability to the X button, and the nodes can be identifies by the blue ring around them.

The skill tree, has Battle Cry nodes in the fourth space, beneath the yellow-ringed Spider nodes. You will need to reach at least level six before you can earn this Achievement, since it requires a minimum of 17 Skill Points (6 in the first node, 6 in the second, 4 in the Spider node, and 1 for the Battle Cry node).