Kousoku Sentai Turboranger Season 1 Episode 50 The Dreadful Great Seal ( Air Date 1990-02-16 ) Genre Sci-Fi & Fantasy, Action & Adventure category. Overview "Five high school students transform into Turborangers to defend the Earth from the Boma Hundred Tribes, who awoke from a 20,000 year-long sleep. They engage in battle using weapons developed by Doctor Dazai.".