Casshan: Robot Hunter

Under the iron grip of the Black King — a superintelligent robot who turned machines designed to help people into an army that hunts them instead — Tetsuya Azuma watches humanity crumble. With survivors either enslaved or scattered, Tetsuya makes a drastic call: he fuses himself with a mechanical body to become Casshan, a cyborg powerful enough to actually push back. It's not a clean hero origin. He's not fully human anymore, and the weight of that sits with him through every fight. Alongside Luna, a key figure in the human resistance, and his robotic dog Friender, Casshan takes the fight directly to the Neoroids — and the action does not hold back. This is a 4-episode OVA from 1993, so it moves fast and stays lean. The animation has that specific 90s Tatsunoko look — cel-drawn, occasionally gritty, with combat sequences that feel kinetic and grounded compared to flashier modern productions. The themes underneath — identity, sacrifice, what separates human from machine — give it more weight than a straightforward action premise might suggest. If you liked Tekkaman Blade or Cyborg 009, this hits a similar tone: dark, physical, and quietly melancholic beneath the battles. Fans of Megazone 23 who appreciate dystopian sci-fi with emotional stakes will probably find something here worth their time. Four episodes means a real commitment is basically nothing, and it earns those hours.