The titular mecha Mazinkaiser SKL OVA, though only called Kaiser by the characters. Unlike the Mazinkaiser featured in the first OAV series, manga, and in video games, this version of Mazinkaiser has a completely different design, sporting a more demonic look. One of the biggest changes is the Kaiser Pilder, the aircraft used to dock onto the crown of Mazinkaiser to control it. It has been renamed as the "Skull Pilder" and redesigned to resemble more of a human skull hence its name. The Skull Pilder also requires two pilots to control it, unlike the Kaiser Pilder where it is controlled by a single pilot. Another notable change is the eyelids having a blue color as opposed to yellow from past Mazingers. A skull in the center of Mazinkaizer SKL's chest is used in place of the "Z" symbol from the original Mazinkaiser.
The weapons for Mazinkaizer SKL are also different from that of the original Mazinkaiser. This incarnation of Mazinkaizer is equipped with a weapon known as the "Ganzantou", a gigantic sword attached to its back. The sword's handle can be extended so it can be used as a pole weapon. The spikes extending at the other side of the Ganzatou's blade is designed to tear apart the innards of its target, as seen in the promotional images.
Another weapon unique to Mazinkaizer SKL are the "Breast Triggers". Attached to Mazinkaizer SKL's chest area, they are a pair of handguns SKL can use to shoot its enemies from mid-range. Blades are also attached to the nozzle and beneath the handle of each handgun, allowing the Mazinkaizer SKL to slash at enemies up close. They can also be merged into a battle axe type weapon akin to the Getter Tomahawk and used as a melee weapon. When the Breast Triggers are not in use, they are holstered to the chest, which forms a resemblance of Devilman's face.
When combined with the Wingle's Scrander the Wing Cross, SKL's limiter is released, allowing it to fight at full power, changing its eye color from blue to yellow, as well as unlocking a new set of weapons, which are variations of those from past Mazingers. The Tornado Crusher Punch is SKL's version of the Rocket Punch, with the difference being that Ken Kaido is able to guide them to their target after they are deployed. The Breast Triggers fire laser beams as opposed to solid rounds. The Rust Stream is SKL's version of the Rust Tornado from Mazinkaiser. The Thor Hammer Breaker allows SKL to shoot a huge bolt of lightning towards its target from the Ganzantou, similar to Great Mazinger's Thunder Break. Finally, the Inferno Blaster is SKL's most powerful attack, acting similar to the Fire Blaster from Mazinkaiser.