Velis first met Mydia at Rabanastre, having annual meetings at the city's Southgate until he left to fight in the war against Archadian Empire. Velis died in the battle of Nalbina Fortress, one of the many whose names were placed on the memorial at the Paramina Rift. His death drove Mydia mad with rage, leading her on the path of becoming the Judge of Wings. Feolthanos lured Mydia to Lemurés, where she believed she could bring her love back to life. However, she was deceived by Feolthanos, and she was only able to create a Yarhi in Velis's form.
While stranded on Tswarra, Isle of the Lost, Vaan and company come across "Velis" as he was being attacked by Yarhi. He initially does not say much, but becomes close to Penelo after she heals his injuries. He eventually opens up to her and tells her that he is looking for someone. They end up spending a lot of time together, causing Vaan to become jealous of the two.
Once Velis reveals to Penelo the truth about himself, Mydia arrives and turns him into his true form, the Yarhi, Odin. The party is forced to fight him, but Penelo is unable to hurt her friend and holds back. Vaan hesitates at the last second when he is about to defeat him, so Llyud finishes Velis off himself.
Later, the Ymir Qul Underground sends Vaan and his four friends to the world of the Yarhi, Lesrekta, Isle of Illusions, where they face Velis again. Upon his defeat, he tells them about Mydia and the truth behind the auracite, and then Velis turns himself into the godblade, Anastasia. After defeating him, the player can unlock the Yarhi Odin on the Ring of Pacts.