Alex Summers enters X-Men #54 as Scott's younger brother, and almost immediately somebody wants to turn him into a power source.

Alex Summers enters X-Men #54 as Scott's younger brother, and almost immediately somebody wants to turn him into a power source. The Living Pharaoh material brings out Alex's ability to absorb cosmic energy and release it as plasma. His connection to the villain's power makes him valuable before he understands much about what he can do. That's an ugly introduction to being a mutant. You discover you can hurt people, somebody starts explaining how useful you are to them, and your brother is already an X-Man with years of experience you don't have. Alex isn't just a second Cyclops with a different beam. Scott has built his life around managing his power and doing the job. Alex spends a lot of this period wondering whether he wants that job at all.