To get this achievement, you must reach level 10 and get the tank role. In order to do this, Fire or Ice (with The Battle for Earth DLC earth is also included for the element choices) must be your power set, which you choose when you create your character. User Vegetall on GameFAQ's wrote a guide located here
http://www.gamefaqs.com/boards/950873-dc-universe-online/610... for help grinding. As well, here is a video to help:
https://www.youtube.com/watch?time_continue=3&v=ELXWBbw3...Credit to King_Titan215 for his video.
Please do keep in mind that both guides are merely what the player does for theirs. You may very well know of a better way. If so, please do post in the comments so I can update this guide with your video as well!