|“||Evil doesn't change. It just wears a new face.||”|
He is the tallest member of the Blitzkrieg Boys.
He is generally a very quiet person. But when he speaks during battle, to his opponents, he speaks in volumes. He is a competitive player and doesn't like to lose.
Spencer is seen with the rest of the Demolition Boys as they all carry out Boris's orders throughout the finals of the World Championships. He and Bryan first bladed in "First Strike", where they would defeat Max after his battle against Ian, and Spencer then took Draciel away. His most significant role was in the first round of the finals, where he battled Kai and won 2-0, taking Dranzer in the process.
In G-Revolution, Spencer almost made it to the team, and actually did for one or two days, until Kai decided to join the Blitzkrieg Boys.
After the training he had accepted to do with Kai and Bryan, Spencer collapsed from exhaustion.
Bryan later appears alongside Tala and Spencer to bring down Boris and BEGA. The trio easily defeats the BEGA water gang and face Garland next. Bryan and Spencer battle against Garland but don't stand a chance. The two lose and their beys are severely damaged by Apollon's Radiant Thunder. They were not able to witness Tala's battle as they had collapsed soon after their own battle.
In the Japanese exclusive ending/epilogue he is seen with the rest of the Blitzkrieg Boys back in Russia.
Spencer received his Beyblade from Boris' organization. The original Seaborg was never shown in the anime as Spencer uses Seaborg 2. Seaborg 2 is a basic attack based blade that has a three-sided attack ring and a 8 wide weight disk.
Seaborg is shown when combined with it's bit beast it has an enormous advantage when paired with stadiums with water, with this edge it became powerful enough to defeat Kai.
In G-Revolution, Spencer is shown with Seaborg 2 but this time it has a larger blade base, presumably for the engine gear.
|Max Tate (tag w/ Bryan)||Episode 46||Win|
|Kai Hiwatari||Episode 48||Win|
|Tala||G-Revolution Episode 07||Lose|
|Kai Hiwatari (tag w/ Bryan)||Lose|
|BEGA Training Squad (tag w/ Tala & Bryan)||G-Revolution Episode 35||Win|
|Garland Siebald (tag w/ Bryan)||G-Revolution Episode 35||Lose|
- Spencer's Beyblade Launcher is pistol-shaped, as well as the rest of the team
- He is the largest in his group in size (Tala, Bryan, Ian, Kai).
- The name "Sergei" is a Russian-Bulgarian name. "Spencer" is from English and means "donor". Contrary to popular belief, Sergei has no official surname.
- He does not like being connected to anything.