YMMV / Shin Mazinger Zero

• Complete Monster: The Juzo Kabuto of the second timeline—despite his short appearance—is responsible for the events of the series. An egomaniacal scientist and grandfather of Koji Kabuto that got information from a version of himself of an alternate future. Juzo Kabuto betrays his family and creates the Mazinger to use it in a war of conquest against the entire world, murdering entire armies and destroying cities until all world leaders bow to him. Bored with his victory and frustrated after realizing that his Mazinger wasn't the most powerful version of it that could exist, Juzo burns the world leaders with the Mazinger despite their surrender and orders Minerva X to reset the timeline and share his scientific developments across the world in order to create an actual challenge for himself in another timeline, leading to the rise of Dr. Hell and creating a cycle of tragedy where the world would be destroyed in multiple ways for either Dr. Hell's ambition or the Mazinger's massive power.
• Crosses the Line Twice: Sayaka's pilot suit in Artemis A, which takes the term "Stripperiffic" and beats it over the head with a stick for not being ambitious enough. It looks more like bondage gear than a pilot suit and its appearance in Super Robot Wars X-Ω makes it very clear that that parts of it that aren't black are Sayaka's exposed skin. Just seeing her in it caused Kouji to freeze up to gawk at her during a life and death battle. Oh, and it makes Artemis A into a Motion-Capture Mecha by linking up to several ports on her spine... ...and two in a rather intimate spot. What do the heroes do to keep their focus on Minerva X's recollection of the events that lead to the manga? Kick back with some popcorn and drinks while Hell Gordon pounds on the lab's photon barrier of course!
• Memetic Badass: Even though Mazinger Z codified many Mecha tropes following its debut, the titular machine paled in comparison to other titles decades later, whose eponymous Humongous Mecha had powers that really began eclipsing what Mazinger Z can do; not even the Mazinkaiser had a percentage of what god-tier robots like the Getter Emperor and entities such as Elder God Demonbane have. Mazinger ZERO, thanks to its breadth of Story-Breaker Power and the climax of the story involving The Multiverse by forcing every conceivable Humongous Mecha series ever created to fight ZERO, has bumped this machine to the highest imaginable Power Level in Mecha fiction yet. It's little wonder when Super Robot Wars began adapting this story for some of its installments, Mazinger ZERO is explicitly an In-Universe threat to all parties alike, just like the Manga.
• Tear Jerker:
  • The Downer Beginning, with Kouji losing literally everything before meeting Minerva-X. To wit: his father was murdered, his girlfriend was raped AND killed, he killed the culprit (his grandfather, of all people), lost an arm... and then not only he became a messed-up Woobie, Destroyer of Worlds, but he and Mazinger ended up literally destroying Earth. And for worse, Minerva witnessed everything and couldn't do anything to help.
  • Hell, any time that ZERO is activated can be considered this. To elaborate this is a monster that was once a hero and guardian of the human race. Sure, it was stated that it could become a god or a devil, but most of the time we've been shown the heroic side to it. And then to see it just...degrade itself into what amounts to a selfish all-powerful child who's scared of being forgotten is heart wrenching to say the least.
• Too Bleak, Stopped Caring: The series kicks off with Earth as a desolate wasteland, humanity doomed to extinction, the titular ZERO destroying the world, and the hero being killed and having his soul transferred to another timeline to undo this event. The bleak beginning is one thing, but the fact that the series repeatedly resets the timeline due to ZERO always coming back and destroying humanity (after someone a little less evil sets the stage first) means you'd better not get familiar with a majority of the cast since they're never going to be the same ones from earlier. Plus the constant resets mean every victory in the last timeline is rendered moot and pointless.
• The Woobie: Minerva-X! She's been through nearly 3000 different cycles trying to stop ZERO from rising and she's failed every single time.

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