He and [[Leo]] went to the [[Daimon Area]] to duel the [[Akiza Izinski|Black Rose]]. Dexter had modified his Deck specifically to duel against her. When he first meets [[Yusei Fudo|Yusei]], he was afraid of him due to his [[Criminal mark]], but began to admire him once Leo told him he had customized his and Luna's [[Duel Disk]]s to fit them and was strong enough to enter the [[Fortune Cup]].<ref name="ep14">{{episode|Yu-Gi-Oh! 5D's|14|ref}}</ref>

In episode 150===Pre-World Racing Grand Prix and WRGP===Dexter has enlisted into [[Duel Academy (New Domino)|The New Domino City Duel Academy]] along with Leo, Luna and Akiza. He was in danger of being expelled by the vice-principal, [[Rudolph Heitmann]], he who despises them for having low grades and low-level monsters. He is cheering for saved after Yuseidefeats Heitmann in a duel.<ref name="ep67">{{episode|Yu-Gi-Oh! 5D's|67|ref}}</ref>

===World Turbo Grand Prix===Dexter has enlisted into [[Duel Academy (New Domino)|The New Domino City Duel Academy]] along with Leo, Luna and Akiza. He was in danger of being expelled by the vice-principal, [[Rudolph Heitmann]], who despises them for having low grades and low-level monsters. He is saved after Yusei defeats Heitmann in a duel. Later, he accompanies Leo and Luna into a supposedly haunted forest. Leo wants to turn back, but Dexter reminds him that it was his idea to explore the forest in the first place, and the group continues in. After Luna and Leo lose him (Leo was chasing after Luna when the latter fell into a trance), Dexter runs to [[Poppo Time]] to tell Yusei what has happened. <ref name="ep70"|episode|Yu-Gi-Oh! 5D's|70|ref}}</ref>

He is also frequently seen in the stands along with his friends [[Patty]] and [[Bob]] watching [[Team 5D's]] duels in the [[WRGP]].<ref name="ep98">{{episode|Yu-Gi-Oh! 5D's|98|ref}}</ref><ref name="ep104">{{episode|Yu-Gi-Oh! 5D's|104|ref}}</ref><ref name="ep119">{{episode|Yu-Gi-Oh! 5D's|119|ref}}</ref><ref name="ep125">{{episode|Yu-Gi-Oh! 5D's|125|ref}}</ref> ==Ark Cradle== During Yusei's fight with [[Z-one]], he is seen cheering Yusei on.<ref name="ep150">{{episode|Yu-Gi-Oh! 5D's|150|ref}}</ref>