Teruo Suzuki

Teruo Suzuki (鈴木 照男, Suzuki Teruo) or also known as Arch Orphnoch (アークオルフェノク, Āku Orufenoku) or Orphnoch King. He is an orphaned boy rescued by Naoya Kaido. Unknown to everyone, he's the most powerful Orphnoch in Kamen Rider 555.

Rescued & Orphaned
An anti-social young boy who was orphaned when his parents died in a fire caused by the Barnacle Orphnoch. Teruo was placed in the Sousai Children's Home (創才児童園, Sōsai Jidōen) orphanage run by Smart Brain until Kaido took him to his home and later stayed and lived in Keitarō's laundry mat, unaware of his immense power.

Rise of Orphnoch King
By episode 45, Teruo began to act strangely and was eventually revealed to be the Orphnoch King in Episode 47. Whenever Teruo blacks out, the Orphnoch persona emerges from his shadow to consume the lifeforce of Orphnoch, in which to fully mature. After being taken by Kiba in episode 50, Teruo eventually transformed completely into the Arch Orphnoch which causing him to die and having  the Orphnoch King taking over his  thanks to Kyoji Murakami who fully awakens him by sacrificing his life. Fully awaken, the Arch Orphnoch fully evolved Saeko much to Takuma's fright after beating Faiz. It took Yuji's sacrifice and Faiz Blaster Form's Blaster Crimson Smash to defeat the Arch Orphnoch. But...

Post Battle
After the epic battle between all the riders, it was revealed that the Orphnoch King was powerful enough to withstand the assault from the Kamen Riders. Arch Orphnoch barely survived and was mortally wounded, placed in a stasis tank under Smart Brain's secret facility by the only genetically stable Saeko. Because his fate was never determined, it's unknown will he ever return or remain dormant for eternity.

Kamen Rider Decade: All Riders vs. Dai-Shocker
To be added

Kamen Rider × Super Sentai: Super Hero Taisen
To be added

Kamen Rider Battride Wars
Arch Orphnoch appears as a boss in the video game Kamen Rider Battride Wars.

Ability
The Arch Orphnoch or Orphnoch King is of a special type who possesses the power to "complete" Orphnoch' evolution, removing all traces of humanity in the process while granting long life. Unlike others, the Orphnoch King can disintegrate them instantly.

Portrayal
Teruo Suzuki is portrayed by Kayato Watanabe (渡辺 彼野人). As the Arch Orphnoch, his suit actor was Jiro Okamoto (岡元 次郎).