He is described by having a wild, but straightforward and good-hearted personality. Despite his neutrality about choosing a good or evil side, Lancer prefers only justice. Lancer is said to be around 20 years old (a few years younger than his counterpart), and much like Shirou Emiya, he's not yet mature enough to understand that the world is unreasonable and has an inherent balance of good and evil.
Fate/Prototype spoilers.Lancer seems to fill much the same role as he did before, tracking down the main character in order to eliminate them. While for his counterpart this seemed to be motivated by Shirou witnessing his battle with Archer, in Fate/Prototype Ayaka Sajyou appears to be a predestined Master for the war, leading Lancer to hunt her down. Lancer pierces Ayaka, however unlike her counterpart Ayaka summons her Servant in this instant, leading to Saber's summoning that seemingly negates any harm from his attack.
Sometime later on during the Grail War, Misaya would die due to a curse that had been inflicted upon her. Masterless, he forms a contract with Ayaka, who had lost Saber to Berseker's Master, Sancraid Phahn. It would be here that he would fight off both Berserker and Saber, corrupted and presumably the original version of Saber Alter, while Ayaka takes on the twisted priest who stole her Command Seals to reclaim Saber. His contract with Ayaka is an exchange for her help in killing the zombiefied Misaya.