If you need a target for EB, just go to the first area (insurgent camp) and hit one of the two targets walking around. Wait 10-12 seconds, if EB doesn't pop up hit the other one. After you kill EB, wait a minute or two before trying again. Low energy, minimal experience. Raiding others also works.
I usually return to my base and put my device to sleep. Then I pick up my other device and kill a boss, put that device to sleep and repeat.