For starts I like Ginji's character in the anime and the role he plays.He is such a easy going guy and very friendly.Always wanting to help however the dark side of Ginji is very powerful which causes Ginji a lot of pain.Ginji hates to see when people get hurt I suppose he just can't live with it.However he still acts like his happy-go-lucky self.I think happy-go-lucky goes really well with Ginji.He is also very loyal to his partner Ban Mido.Which I like :D.I love when he goes in his chibi form he is so cute.

Why the name "Polar Opposite Emperor".As you can tell Ginji has two sides one happy-go-lucky the other no so happy-go-lucky.And as always no matter where he went he always seem to have the Emperor feeling.Trying to protect everyone he could and his friends.I also like happy-go-lucky :D

He's the current partner of Ban Mido and was once the fearsome "Lightning Emperor" and the leader of a gang called "The Volts" in the Infinity Fortress. He received the title "Raitei" (literally, "Lightning Emperor") because of his ability to control electricity. This control grants him several unique abilities such as amazing regenerative power as well as the ability to become a human magnet and battery. Despite Ginji's dark past, his demeanor is one of an unassuming, energetic, and friendly boy with a strong sense of justice. He makes friends easily, often without trying - and is trusting and open to an almost naive extent. But when exposed to remnants of his past, he has a tendency to revert to his darker "Lightning Emperor" persona. For comical purposes, he also turns into a droopy chibi, most likely designed after a tare panda. He's frequently beaten up by Ban (comically) for doing stupid things.

Little of his past is known. We do know that his childhood guardian is Takeru Teshimine, then ruler of the Infinity Fortress. Before his departure, Ginji founded "VOLTS", a gang led by The Lightning Emperor, and "The Four Kings of the Volts" to protect the Infinity Fortress from the monsters of the Beltline.

Although sharing the same body as that of Ginji, Raitei is the polar opposite of the happy-go-lucky Ginji. He first came into being when Ginji was a young boy, as the Beltline Monsters invaded the lower levels of the Infinity Fortress. Ginji and a friend of his was escaping from the hunters, when an arrow was shot into Ginji's companion. It took less than the time it takes to blink, but the whole invasion force was annihilated in an instant. From that point on, whenever Ginji is confronted with a difficult situation, emotionally or physically, Raitei appears to make everything that troubles Ginji disappear. However, this ultimately causes more pain for the peaceful Ginji as death is the last thing he ever wants.

The source of Raitei's power is actually the limitless energy currents flowing through the Infinity Fortress and as such, he draws as much power from them as he needs. Sometimes though, this can put the Infinity Fortress in a sticky situation if Raitei calls for more power in a single instant than the tower is capable of producing. For this reason, he is dangerous to the "Brain Trust" in Babylon City who possess the "Archive" (the sum total of human knowledge past, present and future) as he could potentially erase the "Archive" if he blacked out the Infinity Fortress. (This fact was later used by Der Kaiser in the Voodoo Child arc.) During the era of the Volts, only one man was known to have handed the Raitei defeat: Ban Mido. Also, another reason why Ginji/Raitei is so dangerous inside the Infinity Fortress is because his existence is "random" in the Babylon City Archives. This means his existence was not foretold, assumedly unlike Kazuki and Shido, and his entire being inside the Infinity Fortress changes all the prophecies made by the Brain Trust.

Ginji the Lightning LordIn the manga storyline, Ginji reverted to Raitei many times. But, in the Kiryuudo arc, he once lost much of his powers after one such rampage. Fortunately, Shido Fuyuki managed to revive his powers later with the use of his Shikizoku power.

There appears to be a hidden danger whenever Ginji turns into Raitei: If he rampages long enough as Raitei, there is a chance that he might not be able to revert back to Ginji Amano. It's because of this that Ban warns him not to turn into Raitei under any circumstance.

When transformed into Raitei, Ginji glows with a brilliant light and has bolts of electricity (even orbs of plasma at times) flowing around him. His features will also harden and he's merciless towards almost anyone. However, it has been shown that anything that acts like a black hole can defeat Raitei by draining his powers away (as demonstrated by Yukihiko Miroku [although at a later point in the beltline, Raitei blew away the black holes with no problem] and the fight during the Queen's Challenge).

Also, Raitei was able to defeat the Voodoo King, an antagonist in the "Get Back the Lost Time" arc. With this final victory, Raitei disappeared into a pile of dust, from which Amano Ginji was to emerge. Seemingly, Ginji's other self has disappeared forever...

It's been revealed that Raitei was actually created by Ginji's mother, a professor with links to Bablyon City and the Infinity Fortress as a whole.

By Wikipedia