who were the main characters of this season?
Finn the Human, Jake the Dog, The Ice King, Princess Bubblegum and Marceline the Vampire Queen.
Adventure Time (season 10)
Voice actors for the season included Jeremy Shada (Finn the Human), John DiMaggio (Jake the Dog), Tom Kenny (The Ice King), Hynden Walch (Princess Bubblegum), and Olivia Olson (Marceline the Vampire Queen). 
when does the last adventure time episode air September 3, 2018 what is the genre of this series? UNANSWERABLE where was this aired for the first time? September 17, 2017
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Adventure Time (season 10) [SEP] Cast
Voice actors for the season included Jeremy Shada (Finn the Human), John DiMaggio (Jake the Dog), Tom Kenny (The Ice King), Hynden Walch (Princess Bubblegum), and Olivia Olson (Marceline the Vampire Queen). Ward himself provides the voice for several minor characters, including Lumpy Space Princess. Former storyboard artist Niki Yang voiced sentient video-game console BMO in English and Jake's girlfriend, Lady Rainicorn, in Korean. Polly Lou Livingston, a friend of Pendleton Ward's mother Bettie, voiced the small elephant Tree Trunks. Jessica DiCicco voiced Flame Princess, Finn's ex-girlfriend and sovereign of the Fire Kingdom. Andy Milonakis voiced N.E.P.T.R., a sentient robot who makes (and throws) pies.