Answer:
Death Ignorer.
Step-by-step explanation:
According to Edwin Shneidman, there are different kinds of suicidal people.
He defines the death ignorers are individuals who decide to end with their lives without realizing what this truly means (the end of life), this people think that their decision will lead them to the beginning of a new better life.
In the question, Leonard decides to k ill himself in preparation for the alien's arrival who will select members to serve on an interstellar council but the only ones selected will be the ones who shed their physical form. Therefore, Leonard believes that, by doing so, he will be among the selected ones to begin a new better life. Therefore, he is a death ignorer.