Personality & Characteristics
Boris seems to bring either fear or hatred from anybody who knew him at one point of history. For instance, while Kai, Tala, Spencer, Bryan and Ian display much loathing towards the man, younger kids such as Alexander are frightened by him and do anything he orders them to do.
Boris is a cunning planner and is patient enough to lie in wait and plan ahead. He gained ideas from his time as coach to the Demolition boys and power influence from his time under Voltaire. He trialed a team under the name of Barthez Battalion in the 2003 BBA world championships, though left the coaching and directions to Barthez himself. Though the team failed to get anywhere and came overall last in the World Championships, it successfully drew out his own team the Demolition boys into the World Championships, falling into his trap he had set up for them. He then committed a complete take over of the BBA by convincing the committee of the BBA to follow his ideas and buying everyone out.
Boris proposed a idea based on other sports, wherein a handful of professional and elite Bladers dominated the scene, bringing in money and fame to the sport of Beyblade. This would make those who participate in it both rich and famous. On the outside the BEGA League would be glamorous environment, in reality it would end up shutting out most amateur Bladers. The result is that individuals like Tyson would never have been able to simply rise to World Champion status since they were unknowns with no sponsorships or fame under their belt to grab the attention and enter the BEGA competition.
In the first season, he was the Demolition Boys' trainer and also the main authority in the Abbey, but he was secretly given orders from Voltaire, Kai's grandfather. Boris was the one who selected the boys he thought would fit in the monastery to train them to become excellent beybladers who would be part of his army to gain more power. However, his plans are foiled by Tyson, who defeats Tala in the final round and this caused the Demolition Boys' bladers to reform. Voltaire is then presumably arrested while Boris went into hiding.
After the failure of his plans to take over the world, he came back, in G-Revolution, with an organization called BEGA, which takes over the BBA's assets. His goal was to transform Beyblade into a professional sport because, as he said, he was a changed man after he had wandered in Russia and watched kids play Beyblade in the street, telling Tyson and the others that he has turned a "new leaf". Of course, this sounded bizarre to everyone, and, no matter how much he cried while explaining his story, people like the Blitzkrieg Boys knew BEGA was in fact only a way to get more control, again.
Boris was also behind the whole Barthez's Soldiers scandal as he was the one who recruited Barthez (his agent) in the first place as a means to gain attention and win his way through the Championship by cheating. When the BBA Revolution faced the Barthez Battalion, Miguel and the rest of Barthez's team realized the truth and turned on him. As a result, Boris' plans were failed. The Blitzkrieg Boys attempted to personally defeat the BEGA Bladers, but Boris easily has Garland defeat all of them, with Tala sustaining severe injuries. Upon learning the truth, Tyson immediately challenged Boris and the BEGA League to a battle in order to ruin them. Everyone one of Tyson's teammates (Max, Daichi, Kenny, Hilary, and Ray) joined his side except for Kai, who still wanted to have a rematch against Tyson. Though, all was not a loss when the other teams from the World Championships joined them.
During the qualification rounds of BEGA, he was uncaring as to how the match between Brooklyn and Kai played out, as long as the winner was the one he had in mind: Brooklyn. Boris told Hiro that he wanted the battle to be quickly over, and did not even raise an eyebrow at the damage Brooklyn was inflicting at Kai.
In the Justice Five Tournament, Boris was satisfied that his plans were following through with Ming-Ming and Crusher defeating Daichi and Ray, respectively. Before Max battled, Boris told him to win against Mystel so that people wouldn't think BEGA was cheating with a sweep. This also worked out when Max and Mystel tied.
Later in the fourth battle, Kai had arrived to rejoin the G Revolutions, where he would battle against Brooklyn for redemption. Boris felt confident knowing that Brooklyn would defeat Kai like last time, but Kai eventually succeeded in winning and Brooklyn was thrown into a deep depression over his first loss, which caused Boris to get angry that Kai was diverting his plans. In the fifth battle, Tyson got through to Garland in the spirit of Beyblading and defeated him, much to Boris's frustration.
Tired of the G Revolutions foiling his plan, Boris tells Hiro to break through to Brooklyn for the tie-breaker match while sending Crusher and Ming-Ming to Tyson's house in order to weaken him. As Hiro works with Brooklyn, Ming-Ming and Crusher arrive at Tyson's dojo to fulfill their task, but Lee and Rick get in their way and battle them instead. Hiro succeeds in his task, but Crusher and Ming-Ming realize what they're doing is wrong and pull back. As a result, Garland, Crusher, Mystel, and Ming-Ming side with the G Revolutions and begin to defy Boris.
When BEGA fell to Brooklyn's immense power from the final battle, Boris was run over by dozens of fans who were going to see Tyson and Brooklyn battle. He was also peed on by a dog and a bird defecated on his face, but only in the Japanese version. Hiro Granger exposed his true reasons for joining BEGA and resigned from his position there as coach. With all of this occurring, Boris was defeated once more, all thanks to Tyson.
In the manga, Boris was actually only a subordinate to Dr. Zagart, and both worked to learn more about sacred Bit-Beasts so Dr. Zagart could steal them and resuscitate his first son Zeo.
Boris was also related to the Saint Shields, since they temporarily worked for the two men regarding the sacred Bit-Beasts matter.