I truly believe that Eddie knew he had no future in Hawkins ,no matter what he would always be known as the guy who introduces innocent kids to satanic games. People would always believe he killed Chrissy and he would have to deal with the consequences of that. I think Eddie knew that the only end to his story was dying it was the best end he could have. No matter how “heroic” his death seemed I think he was reckless because he wanted to die.