What special features of aztec civilization must be explained?

I believe the special features that must be explain is the reason why they sacrifice human being.
The aztec cultures believed in several Gods that they believe would bring 'wellness' for their society. In order to please these Gods, they believed they should sacrifice something valuable that considered worthy to appetize the Gods, such as human lives.

In the late fifteenth century, a major world power that established colonies in the era of old imperialism was france or germany or spain. their colonial activity was mainly limited to america or africa or asia.