(Capcom's primary storyline)
Dion is a former young dog handler.
In Eastern Europe, he helps his captain Chris Redfield in infiltrating the Winters' home and eliminating Miranda who is under the guise of Mia Winters in an effort to steal the couple's daughter Rosemary Winters. Sometime later, he and other members of the team arrived at the overturn convoy with the escort men killed and Ethan and Rose nowhere to be found.
Dion and his unit arrives at the crash site at 11:35 AM with no sighting of Ethan and Rose. In 12:10 PM, they infiltrated the Village and engages with numbers of different bioweapons, they found evidence of Ethan being in the Village but Rose's location remains unknown. In 13:10 PM, they established a base in the church and plans the operation with him, Emily Berkhoff and John Perlman search a laboratory nearby while the other two in charge with analyzing mold samples and their captain Chris heading to Heisenberg's Factory.
Dion and the others then set up at a research post somewhere in Reservoir to monitor the situation and examine the Mold around the Village. Dion and his teammates are then attacked by the mutated fish creature in the nearby area but all of them made it out alive.
Sometime later, he and the others have eyes on Miranda at the ceremony site, they then report and take screenshots and sends it to him.
After Ethan Winters's supposed death, they are then regrouped to discuss the mission objective which is to terminate Miranda and rescue Rose, Chris then orders them to watch out and terminate any hostile B.O.W with the exception of him being ordered to find out why the BSAA is here in the first place.
After the destruction of the village caused by Ethan, Chris orders them to pick up the rest of their squad and plot a course to BSAA Europe HQ.