In a multi-part mission to help Lex Luthor, you'll be going into STAR labs to assist the genius villain and defeat Steel. When you get into the room where Calculator needs you to buy him time, you'll have a pretty steady flow of incoming targets. AoE the heck out of these. You do have some back up to help you out but there are a lot of incoming mobs.
Once that is taken care of, locate Lex and help him fight Steel. This isn't designed to be a difficult fight, mostly because this zone is only a part of the overall mission. Steel's tough, but I manage to stay on top of him and hack away without wasting any of my consumables. If you're doing the investigations, be sure to run back through the zone and check that you didn't miss any as there are a couple in here.