10 February 2020: Adding Slave Hero to Isekai Quartet hasn't ruined it yet
"Naofumi, what are we going to do inside the Shield Prison?"
Finding out that the cast of Tate no Yuusha no Nariagari (The Rising of the Shield Hero) was joining Isekai Quartet did not exactly fill me with a lot of confidence about its second season (which inexplicably isn't called Isekai Quintet), but it's been okay so far. Then again, the Shield Hero cast hasn't been in the first four episodes very much. Most of my trepidation derives from my fairly negative impressions of Shield Hero as a show (I watched 13 episodes), my lack of interest in the characters, and the rather defensive attitude the franchise's more vocal supporters seem to adopt on the Twitter. These did not seem to be ideal additions to a comedy about characters being portrayed as dipshits.
Aqua is sort of racist, to tell you the truth.
Naturally, the Kono Subarashii Sekai ni Shukufuku wo! cast fits right in, because they're dipshits to begin with. Aqua is a delight—so much so that I want retcons of other Tenchan roles except portrayed as basically Aqua analogs. (For example, Asseylum Vers Allusia from Aldnoah.Zero except with Aqua's personality and intelligence. You can't tell me Slaine's tragic loyalty to Aqua Vers Allusia wouldn't have improved the second season.) Given a choice, I'll definitely take idiots like Aqua over sourpusses like Naofumi when it comes to wacky comedy crossovers.
