Sieg

"Advent, to the top..."

- Sieg's pre-battle catchphrase

Sieg (ジーク) is an Imagin who is unofficially the fifth part of the Den-Liner crew, providing Ryotaro Nogami with Den-O's Wing Form.

Kamen Rider Den-O
Sieg arrived 6 months prior to Ryotaro becoming Den-O, originally intending to forge a contract with a young wealthy woman named Shiori Takayama. But she was pregnant and Sieg ended up inside the baby in a deep sleep until he emerges in physical form with no memory of the wish and believes that he forged a contract with the baby, Yusuke, instead of Shiori as he had planned. Sieg took his "brother" out of the strange area he found them in, only to meet Ryutaros who takes Sieg to the Den-Liner, where the Imagin got his own sleeping car with a lavish bed and Ryutaros helped fill it with stray puppies and kittens. After a series of events that clear Ryotaro of Yusuke's abduction, Sieg uses the human's body to reap the benefits of living with the Takayama family

However, because Yusuke's mind is too young to maintain his existence, Sieg begins to fade away, but not before becoming Den-O Wing Form to fight the Scorpion Imagin. After the Scorpion Imagin is defeated, Ryotaro returns with a Rider Ticket that he got from Shiori that bore the date June 1, 1997, revealing that Sieg did have a contract with her. He then remembers Shiori's wish for her baby to be born safely, fulfilling that contract. With the Den-Liner gang's help, Sieg arrives in the past to live peacefully. However, during the hijack of the Den-Liner, Sieg offers his aid to Ryotaro in the Tarōs' stead as only he could possess Ryotaro's body, deciding to repay his debt to Ryotaro for preventing his disappearance.

He battled the Cobra Imagin in the Edo period while befriending Kotaro. He would aid the Den-Liner gang two more times, aiding in Ryotaro getting stronger and later to assist Ryotaro and the others in defeating Kai's army of Imagin after being retrieved by Naomi. But due to his birth and time with Ryotaro creating a time lag, Sieg is able to maintain his existence as he takes leave in the Den-Liner.

In final episode, Naomi returns Sieg to the present for the latter for the final battle, where he protected Kohana, and he helped the Taros and Deneb defeat the Death Imagin.

Final Countdown
During the events of "Final Countdown", Sieg greets the Den-Liner crew in May 23, 1729 as their contract, offering his help as Wing Form during the epic battle against the revived Imagin. Following a pattern of showing up when help is needed, he appears later to help in the battle of the returning Oni forces.

Here Comes Super Momotaros!
Sieg appears in Kamen Rider Decade when Tsukasa and company were about to enter the World of Kabuto when they get an unexpected visit from the Imagin Sieg. With a manuscript on Sieg's person, it appears that the adventures in the World of Den-O are far from over.

Episode Blue: The Dispatched Imagin is Newtral
Sieg appears in the moment ,when Momotaros and Ryotaro unable to continue, the Owner reassures the DenLiner crew that they still have hope as Sieg arrives, later With the others shocked, the Owner reveals Kotaro's friendship with Teddy saved him and restored their contract. Though the others were confused by the whole point of the Owner's actions, along with Sieg’s appearance, Kotaro believes it was to teach him a valuable lesson as he and Teddy are returned to their time.

Kamen Rider Buttobasoul
Sieg as Kamen Rider Den-O Wing Form is a playable character in Kamen Rider Buttobasoul.

Battle Spirits
Sieg as Kamen Rider Den-O Wing form appears with other Kamen Riders and Monters in Battle Spirits.

Personality
""Kneel down to me!""

- Sieg While in a contract with Shiori, Sieg gained a physical form based on the ballet Swan Lake (白鳥の湖), with "Swan" written on his breast plate, named after its character Prince Siegfried (ジークフリート王子). Because of his princely mannerisms, Sieg becomes easily infuriated when treated with disrespect. During his first time on the Den-Liner, he demanded that the others call him "Prince" (プリンス) until he got hit by Hana, calling her "Princess" (姫) since as he called the Taros his "friends". After his return, Sieg refers to the Tarōs as either his "family" instead of his "friend" phrasing, or his "retainers".

Abilites

 * Reduction of size:Because he was "born" in 2007, Sieg possesses the unique ability of shrinking other Imagin to four inches in height for a bit of time with the phrase "Kneel down to me!" (頭が高い!). In the Imagin Anime OVA, Sieg had an additional power "Super-Ultra Kneel down to me!" (スーパーウルトラ頭が高い!) that allows him to shrink everything in sight, even an entire planet.


 * Possession:Whenever Sieg posses someone, the person gains white goldish, white pupils, and white hair streaks. Said person will also obtain a white feathery scarf.

Devices

 * Den-O Belt - Transformation belt
 * Rider Pass - Train pass used to invoke his transformation

Weapons

 * Combination Armament DenGasher - Den-O's primary weapon, due to how it appeared when used by respective Imagin, Wing Form's took the form of Handaxe Mode (ハンドアックスモード) and Boomerang Mode (ブーメランモード).

Portrayal
Sieg is voiced by Shin-ichiro Miki (三木 眞一郎) who will later voice as Listol in HUGtto! Pretty Cure. In both his Imagin form and as Kamen Rider Den-O (Wing Form), his suit actor is Naoki Nagase (永瀬 尚希).

While possessing others, he is portrayed by their respective actors while retaining his voice.
 * As S-Ryotaro, he is portrayed by Takeru Satoh (佐藤 健).
 * As S-Tsukasa in Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship, he is portrayed by Masahiro Inoue (井上 正大).

Appearances
NaNs