Alexei Dinoia is Commandant of the Imperial Knights
and serves as a major antagonist of Tales of Vesperia.
In early part of the game, Alexei is the commandant of the Imperial Knights, without anyone other than Khroma knowing of his evil plans. His ambition took him to betraying the army and even still a lot of soldiers followed his beliefs. Flynn Scifo took his place after his death.
At Zaude, the party finds Alexei in the deepest level, trying to figure out the formula to make it work. Alexei tries to escape to the top, but the party finally attacks and confronts him. Alexei is defeated, but while fighting the group, he was still analyzing Zaude. Alexei tries to activate it, only to be stopped by Yuri. Then, everyone witnesses the Adepaghos's arrival (in fact, the Shrine of Zaude wasn't a weapon like Alexei thought, but rather a barrier that the ancients used to seal away the Adepaghos, since they weren't able to destroy it ) and the death of Alexei, who was injured by Yuri and was crushed by an enormous piece of Apatheia. Alexei had tears in his eyes before he died.
As expected from the Commandant of the Imperial Knights, Alexei is shown to be a formidable combatant and can be considered one of the hardest bosses in the game. He has an array of powerful Strike Artes, such as Ill Wind, Guardian Frost, Radiant Dragon, and Raging Ice Fang. Alexei is also known to have very dangerous spells like Tidal Wave and Holy Rain. But what is probably Alexei's most devastating attack is his Mystic Arte, Brilliant Cataclysm. Alexei transforms his sword into a shichishito. Then he throws it and hits one of his targets then it disappears. The sword reappears and hits the same target again. Finally the shichishito stabs the ground and a giant eruption of light damages the party.