The sentry will win, and not using the “death seed” version of the sentry as that really was immaterial. The Sentry with his power set can defeat the Mad Titan regardless that the avengers along with other teams were unable to. Most pertinently, however, is the fact that there is precedent in the comic books for the Sentry being very useful in the Microverse - which is essentially … Let's see: Sentry tore apart Ares: And also killed Loki: Although Thor possesses greater power than those two, the same outcome is certain.