Article continues below advertisementConan O'Brien returned to the Oscars stage Sunday night with a fast-paced opening monologue that blended celebrity roasts, pointed political humor and an unexpectedly earnest reflection on global turmoil.Hosting the 98th Academy Awards for the second year in a row, the late-night veteran opened the ceremony at the Dolby Theatre in Los Angeles with a barrage of jokes targeting Hollywood figures, streaming giants and current events - before shifting tone near the end of his 15-minute introduction.