How does Modern day Aztec look like right now?

Yeah you answered your own question basically heh. However, many of today's Mexicans are a blend of those Amerindians (btw not all were Aztecs as there were also Mayans, Olmecs, Zapotecs, etc.) and the Spaniards and other Europeans. The average Mexican mestizo is said to be genetically a bit more Amerindian than European, but you can see many evenly blended mestizos as well as mestizos with more European ancestry in northern Mexico. Many there are lighter-skinned, hairier, with longer faces, and often wavy hair, and some even have lighter hair and eyes.