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Official Site: Marvel Comics

The Time Variance Authority (or TVA) is a fictional organization, a group of timeline monitors in the Marvel Universe. They first appeared in Thor vol. 1 #372 (October 1986). Created by Walt Simonson and Sal Buscema, the TVA originally paid homage to long-time Marvel writer/editor, and continuity expert, Mark Gruenwald: the TVA staff were all clones of Gruenwald.

The TVA claims responsibility for monitoring the multiverse and can prune timelines if they're deemed too dangerous to exist. They also take action to prevent other beings from altering the past or future. They were first seen, allowing Justice Peace, a lawman from the future, to travel to the 20th century in order to stop the killer Zaniac. Peace is able to succeed in his mission thanks to the assistance of Thor.

Despite their claims, the TVA's influence over time is not absolute. The scope of their influence is bordered by Alioth in the distant past as well as Kang the Conqueror, the Delubric Consortium, and Revelation at different eras throughout the timescape. There have also been numerous incidents of time travel or reality tampering where the TVA has failed to interfere.

At the End of Time, the last Director of the TVA creates the Time Keepers, the last three beings who exist in the remaining timeline in the universe; however this process also ends up creating the Time Twisters, a trio of beings who imperiled all realities until stopped by Thor and other members of the Avengers.

Time Variance Authority has not been a contender in any CBUB matches.