Sequeiria is a member of the Bagshaw Clan, like the dragonblood warrior the Bagshaw Clan has too some legacy of a divine beast.
Linley first encounter with Sequeiria happen at the trade castle of Miluo Island. When seeing Delia clothe's , the youg master of the clan wanted to buy it.
The first time his guards said that he will purchase the clothe for twice their original price but Linley party refused. Then he tried to buy it for the original price and finaly he got angry and said that they will have to offer it.
Yet Linley party still refused and killed dozen of Highod guards who Sequeira had sent. Upon seeing this Sequeiria went to his home not daring to act against Linley.
The second time Sequeiria encounter Linley party is when he and his men went to kill Cesar because his wife had Cesar child in her womb. Thus Linley fought against one red robbed of their clan and ultimately surrendered to the family for one hundred year.
Sequeiria was the one who shown the path to the secret record of the clan. On the way he said that Cecily was no more on the Island.
The last time we see him was when he tried to make Linley kneel before him thinking that his soul was manipulated. Unfortunetely for him, it was not and his father slapped him. The clan let Linley leave and Sequeiria saw Linley leave.