[Sunred]

FYI Momotaros is based off the Japanese folklore Momotaro(which translates to peach boy), a story of a boy born from a gigantic peach from who knows where that drifted down a stream and picked up by an elderly couple Kal-El style. Boy grew up and later being fed up with the oni trying to mess up their land he went, "Screw them onis, I'mma kick their arses." and went on an epic journey of asskicking towards Onigashima, an island where the onis dwelled. With the help of a dog, monkey, and a pheasant, Momotaro bumrushed the area, kicked some oni ass, got some loot, and lived happily ever after. That is the gist of it.
Design-wise momotaros is based off the oni from this story, while Den-O Sword Form is based off of Momotaro. The compound eyes symbolize the peach that split in two when Momotaro was born and the red chest armor is I believe is supposed to resemble the jinbaori that Momotaro is commonly known to wear in the story when illustrated or depicted in media. And that is also why when the Denliner goes guns blazing part of it transforms into a dog, monkey, and a pheasant.