In the Arrowverse's multiverse, a character based on Bruce Lee exists thanks to the Crisis on Infinite Earths event. Despite lacking some popular DC names like Wonder Woman or Green Lantern, the Arrowverse managed to create a cohesive DC Universe that spanned over a decade. Crisis on Infinite Earths celebrated this universe by bringing together all the Arrowverse shows and referencing various other DC properties.

This five-episode event had a significant impact on the franchise and its characters. Loosely based on DC Comics' Crisis on Infinite Earths, the Arrowverse crossover saw heroes fighting to save all known realities from destruction.

The Crisis on Infinite Earths event expanded the franchise's lore, incorporating numerous properties into Arrowverse canon through surprising returns and deep-cut DC cameos.

One notable cameo in Crisis on Infinite Earths was Burt Ward reprising his role as Robin from the 1966 Batman series. His scene, set on Earth-66, made the classic Batman show part of the Arrowverse canon. This also confirmed that The Green Hornet, in which Van Williams and Bruce Lee appeared as the Green Hornet and Kato, respectively, is part of the Arrowverse's multiverse.

Decades before the Arrowverse's team-up episodes, Batman had a crossover with The Green Hornet in 1967 as part of Batman season 2.

The two shows initially clashed but eventually joined forces, leading to a fight between Robin and Kato. This crossover was followed by a comic book sequel titled Batman '66 Meets The Green Hornet, written by Kevin Smith.

The Crisis on Infinite Earths event also made several other characters canon in the Arrowverse. For instance, Robert Wuhl's return as Alex Knox from Tim Burton's Batman movies confirmed their existence in the multiverse. References to Catwoman connected Halle Berry's portrayal to the Arrowverse as well. Ashley Scott's cameo as Huntress from Birds of Prey indicated that characters like Batman and Harley Quinn were part of the Arrowverse's multiverse.

Furthermore, Crisis on Infinite Earths tied in with the Green Lantern Corps from the 2011 Green Lantern film, validating the existence of Ryan Reynolds' Hal Jordan in the Arrowverse. Brandon Routh's return as Superman, playing the same character Christopher Reeve portrayed, implied that Helen Slater's Supergirl was also part of the multiverse. The event even connected the CW shows to the DCEU through Ezra Miller's cameo.

Overall, Crisis on Infinite Earths expanded the Arrowverse's universe by making numerous DC properties and characters canon. The event showcased the franchise's ability to create a cohesive DC Universe, even without some of the most prominent names, and celebrated the diverse legacy of DC comics.