 The war had gone on for 16 years minimum; it ended abruptly after the Skrulls shot a barrage of missiles at Majesdane, who retaliated.Another prominent alien race is the Watchers, immortal and wise beings who watch over the Marvel Universe and have taken a sacred vow not to intervene in events, though the Watcher assigned to Earth, Uatu, has violated this oath on several occasions.The Elders of the Universe are ancient aliens who have often had a great impact on many worlds for billions of years, acting alone or as a group.