Saico-Tek was created by Brushogun under coercion by Uehara Daizo, a glory-hounding ex-police officer of the Tokyo Police Department. Originally, Saico-Tek was created for the sole purpose of profiling Daizo as a hero, playing the role of the villain which would be captured by Daizo at his convenience.
At some point, however, Brushogun managed to exert some degree over his creations to create a Saico-Tek who would follow his will instead. As means of a call for help, Brushogun sent a pink-and-blue Saico-Tek to wreak havoc in Jump City and thus attract the attention of the Teen Titans. Saico-Tek was captured and questioned by Robin; he revealed the name of his creator just before he kicked open the fire sprinklers in the questioning room, erasing himself.
Following the clue, the Titans made to Tokyo, where Daizo met them and quickly assured them that Brushogun was merely an urban myth. When Robin would not cease his investigation, Daizo sent a pink Saico-Tek to attack him. Robin prevailed, but in the process he ended up beating up Saico-Tek so viciously that he appeared to have murdered him. As a consequence, he was imprisoned and the Teen Titans were denounced as enemies of the state.
Following that, Saico-Tek, in multiple incarnations, made his final appearances as a mere henchman obeying Daizo' instructions to take down the Titans. When Brushogun was freed by Robin and died, however, Saico-Tek and all of his fellow creations created by Brushogun's power likewise ceased to exist.
Powers and Abilities
Abilities-wise, Saico-Tek was a high-tech version of a murderous assassin, an expert in martial arts and acrobatics. He possessed several weapons in his arsenal, chiefly high-tech shuriken which would explode in a cloud of colored smoke on impact or after a short time delay, and a rocket pack which enabled him to fly.
As a being composed of magical ink, Saico-Tek possessed any abilities bestowed upon him by his creator. The first Saico-Tek demonstrated the power to regenerate any damage, to the point of regrowing lost limbs; an ability which subsequent versions apparently did not possess. However, as a creature of ink, he is highly vulnerable to water and would dissolve instantly upon contact with it.
Saico-Tek closely resembles a Power Ranger, or more accurately, a Japanese Super Sentai Action Hero, which inspired the creation of the Power Rangers. Sentai means fighting force in Japanese.
The first Saico-Tek's "half-and-half" design is similar to Kikaider's.
The second Saico-Tek heavily resembles one of the various incarnations of the popular Japanese superhero Kamen Rider.
His name is a play on the pronunciation of the English words "psycho" and "tech(nology)" and also on the word "psychotic".
The word saico/"saiko" means 'latest', and tek is obivously a misspelling of 'tech' which happens in Japan due to the fact that the word is pronounced te-ku (through katagana which is basically a reverse romanization of worlds).
In the movie, after Robin captured Saico-Tek in Jump City and brought him back to the Tower for questioning, Saico-Tek set off the sprinkler to disintegrate himself, since he was made from paint. When the Titans questioned how he disappeared (they didn't know at the time he was made from paint), Beast Boy suggested he "wasn't waterproof". While the Titans were angered at his attempt to make a joke, his joke foreshadowed Saico-Tek's true nature and turned out to be correct.