This article needs to be converted into past tense. It also needs to be about the character, not a plot summary of any/all stories he appears in.
Kreos was positioned at one of the ionizing towers on Skaro, where he met the Doctor and his compainions after they returned to the planet using the TARDIS' fast return switch. Realizing that these strangers are the travellers who helped the Thals fight back agianst the Daleks, he takes them to the Thal City to meet their leader Damadus and their head scientist Tryana.
Kreos joined the Doctor, Ian, Tryana and other Thal soldiers to go to the Dalek City to find Susan and Tryana's son Jyden. After arriving in the city, they reach the secret level below the city that Susan and Jyden discovered and Tryana opens access to a hidden chamber. The Doctor, Ian and Tryana step past the threshold of the hidden chamber, which closes leaving Kreos and his soldiers on the other side. Soon after, the Doctor, Susan, ian, Tryana and Jyden exit the chamber and are reunited with Kreos, however they are with two unarmed Daleks that ask to be taken back to the Thal city as emissaries, so him, Susan, Jyden and the 2 Dalek travel back to the city.
Kreos, Susan and Jyden return to the city where they meet with Damadus and Barbara, he orders the two Daleks to enter the Great Hall and they begin speaking with Damadus, Kreos explains that Tryana has been working with the Daleks and that the ionizing towers are the Daleks' own invention. He orders Jyden and Susan to wait in Tryana's quaters and prepares for Damadus to address the Thal people. When the Daleks begin their attack of the Thal city, Kreos orders his soldiers to protect Damadus, but Barbara tells them to retreat when it electrifies its casing. Barabara, Ian, Damadus and Kreos try to trick the Dalek into destroying it by using Kreos's tunic to insulate the static electricity to its casing, like what Susan did when Alydon gave her his cape. They successfully trick the Dalek and push it over the side of the roof.
They return to Tryana's quaters to see only Jyden inside, explaining that Susan was taken by a Dalek. Damadus and Barbara remain in the city to hold back the Daleks when Kreos, Ian, Jyden and a team of soldiers try to disable the ionizing tower under Dalek control and rescue the Doctor and Susan. Ian and Jyden through the tunnels beneath the city while Kreos and his team go through the jungle, before leaving, Barbara give Kreos her wristwatch so they know when to attack the tower. Kreos and his soldier wait in the jungle near the tower until the hands of the watch reach 12, when it does, they advace to the tower and the Dalek guards are destroyed by Ian in a empty Dalek casing from Tryana's laboratory, successfully securing the tower. The Doctor begins to reprogram the tower while Ian and Kreos return to the Thal city to help the others, when they arrive back in the city, they see that the ionizing tower's discharges are destroying the Daleks. When the Daleks retreated, they regrouped with Damadus and Barbara and contact the Doctor using Kreos's radio, telling them to go ahead with his plan. Kreos and Ian enter the Thal city's generator room and overload the output to the Dalek city, killing the Daleks and destroying their city.
After the Daleks defeat, Kreos, Damadus and Jyden bid farewell to the Doctor and his compainons. (AUDIO: Return to Skaro)