The Flash added another superhero to the team in Season 4 with the introduction of Ralph Dibny, a metahuman who would go on to be known as Elongated Man. While he didn't seem to be a good fit for the superhero life in his first few appearances on the series after being turned into a meta courtesy of The Thinker, he warmed up to the idea of stretching his hero muscles. According to The Flash showrunner Todd Helbing, Elongated Man will be more like Batman in Season 5:
Ralph Dibny may not be considered "The World's Greatest Detective" in DC Comics, but the character is nonetheless known for having detective chops that put him on par with the Caped Crusader. Batman himself is not slated to appear in the Arrow-verse at this point (although another Gotham City superhero will debut in the 2018-2019 TV season); still, Ralph will apparently begin to showcase his detective skills in a way that hasn't happened on The Flash before.
Barry and Joe didn't have the highest opinions of Ralph's investigative potential after their history with him at CCPD, and Ralph was killed off for a time, which naturally put an end to any exploration of his skills as a detective. Now that actor Hartley Sawyer is a series regular for Season 5, the character will likely have more time in the spotlight. Todd Helbing's comments to Newsarama indicate that Ralph will have an investigative journey throughout the new season. Elongated Man will have more to do than elongate.
While Ralph will presumably do a lot of his detecting in civvies, I have to wonder if his superhero suit will get an upgrade in Season 5 to give him some Batman-esque gadgets. Barry's new suit shows some fascinating changes, some of which will come about due to the arrival of Nora with her future tech. Ralph technically didn't get a whole lot of wear out of his suit given his untimely (although ultimately temporary) death, so he may be stretching in his old suit.
Since Hartley Sawyer isn't the only actor to get a bump up to series regular status, there may be more characters competing for screentime, and screentime may not be best allotted to a new suit. Interestingly, Hartley Sawyer sees some similarities between Ralph and another notable character in pop culture, even if that character wouldn't be caught dead in a cape and a cowl.
Team Flash will undoubtedly need all hands on deck thanks to complications of Nora's arrival, the introduction of the new villain, and all the other craziness teased in the first trailer for Season 5. If you're not up on all the newcomers to the The Flash and The CW's other shared universe superhero shows, take a look at our breakdown of all the new Arrow-verse characters coming to the new seasons. For the important superhero premiere dates in the not-too-distant future, check out our fall TV schedule.