Children of the Lens by E.E. Smith

Worsel the Velantian, hard and durable and long-lived as Velantians are, had in twenty Tellurian years changed scarcely at all. As the first Lensman and the only Second-Stage Lensman of his race, the twenty years had been very fully occupied indeed.

He had solved the varied technological and administrative problems incident to the welding of Velantia into the structure of Civilization. He had worked at the many tasks which, in the opinion of the Galactic Council, fitted his peculiarly individual talents. In his "spare" time he had sought out in various parts of two galaxies, and had ruthlessly slain, widely-scattered groups of the Overlords of Delgon.