* CompleteMonster:
** Kazukiyo is the eldest son from the Gowa family. He assassinates a minister of justice in what looks like a tragic road accident, has soldiers injected with PsychoSerum and forced to pilot the series' mecha for 36 hours straight (something that his brother [[MadScientist Kiyotsugu]] [[EvenEvilHasStandards refuses to do]]), provide assistances to a WellIntentionedExtremist, allowing him to stage a coup, uses his own little sister Misuzu in an experiment due to her powers as a ''kai'' (empath that can synch with the HumongousMecha from the series) (something that, again, Kiyotsugu objects to), and commits [[spoiler:{{patricide}} (and when his dad was trying to ''save'' Misuzu from him)]] in order to achieve his goal of power.
** His very ancient predecessor, Tsuna Watanabe, isn't any better, deliberately having the city of Kyoto set on fire, letting the firestorm of Gasaraki be summoned, and then torturing Yushiro by shooting him in the knees with arrows when he refuses to let the summoning continue.
* NightmareFuel: During the final battle, [[spoiler: where the artificial muscles in Yushiro's TA break out of their confines and begin wrapping around the opposing Mecha to merge with it's artificial muscles, the end result is the enemy mecha getting crushed in a bearhug.]]
** The "Firestorm of Gasaraki" that occurs during the flashback to [[FeudalJapan Feudal-era Japan.]]
** The Kugai.
* NotSoCrazyAnymore: The United States invades a Middle-Eastern dictatorship in pursuit of weapons of mass destruction that apparently never existed...
** Also the idea of using unmanned flying/gliding drones for reconnaissance.
*** And the US being almost crippled by an economic collapse.