In Blood Omen 2, Sebastian is encountered in a boss battle. The boss fight takes place at the heart of the Main Factory of the Industrial Quarter at the end of Chapter 6:The Nexus Stone. When Kain entered the boss chamber, he was raised on a dias to the Nexus Stone suspended above him, however as Kain approached the stone, Sebastian revealed himself. After a short conversation, "Jon" (Sebastian's Industrial Worker confederate) lowered the dias into the chamber below and activated the steam jets, beginning the battle.
A 'regular' combat battle, with a twist, as harmful steam jets rotate around the room. Sebastian used regular enemy combat techniques, including a red unblockable spin kick attack and a yellow power attack, in addition to an extended five hit combination (usually followed by a red attack). Kain had to hold the center platform and, along with blocking (thus filling the Rage Bar) and dodging attacks, the most useful technique was to knock Sebastian into the steam jets; either by using Fury, a combination, or a well timed grab attempt (when Sebastian tired); This burnt Sebastian, causing further damaging him, and causing him to 'telegraph' a red unblockable charge attack at Kain (which can be dodged and countered with Fury or combinations). When sufficiently damaged Sebastian changed tactics[Blood Omen 2]. Another option is to run in circles, getting close to the steam jets and avoiding them at the last moment. Sebastian will often get burnt. After a few of this episodes you will go to next phase.
Sebastian began to run in a circle around the walls of the chamber and a 'vortex' formed in the center of the room, forcing Kain off the center platform and into the path of the rotating steam jets. Kain had to move around the room following the steam jets as they circled the room, until Sebastian yelled a warning at Kain and stopped running; holding onto a wall and preparing to jump attack Kain. Kain however, could avoid this attack by positioning himself behind the vortex, causing Sebastian to jump into it himself. Sebastian would then begin running again (with the jets moving in the opposite direction) and Kain could repeat the above process until Sebastian was sufficiently damaged to order the dias to be raised[Blood Omen 2].
Sebastian had his accomplice raise the platform up to the Nexus Stone and attempted to destroy the stone himself (should he succeed, the resulting explosion will kill Kain, and presumably Sebastian) but Kain can prevent this by simply jumping up to the platform, making Sebastian jump off it. From the platform, Kain could see and Charm Sebastian's accomplice into activating the steam jets below, forcing Sebastian to jump back up to the tiny platform. The final sequence of the battle is an intense regularcombat fight in small area; atop the dias and surrounded by steam. Sebastian used combos and red attacks, but these could be countered by Kain's own combos and Fury strike; and Kain could also grab-throw Sebastian into the steam below[Blood Omen 2]. When defeated Sebastian fell off the platform into the steam below and Kain joined him as the steam subsided. Sebastian then revealed that the Nexus Stone had been linked to the Device; a great weapon buried underneath Meridian. As Sebastian died, Kain absorbed the Dark Gift Berserk from him.
- The usage of Sebastian's Dark Gift, Berserk, is incredibly inconsistent with the manner in which Sebastian uses it (Sebastian only uses a regular combo and regular 'power moves', none of which resemble the Berserk combo[Blood Omen 2]). This is because the Berserk gift itself underwent changes during development; originally being called "Speed" and allowing Kain a time manipulation effect - similar to Slow Time from Blood Omen[Blood Omen] and the TimeReaver spell from Defiance[Defiance]; Sebastian uses a prominent 'speed-like' effect in his boss battle.
- Sebastian is notably committed to his cause in the boss battle; knowingly attempting to destroy the Nexus Stone, which would have killed himself and Kain in the process. His relationship with Kain also causes Kain to tell a rare (if not unique) lie  - as Kain offers to spare Sebastian's life; an offer which they both acknowledge is a poor lie.
- An unused, final line of dialogue for Sebastian (as he dies) is present in Blood Omen 2's data files and original script, but is never spoken in-game. Sebastian utters, "Perhaps, after all, we will go to the grave together..."
- Sebastian: "One of Kain's old vampire acquaintances now helping the Sarafan. Seek him out in the Industrial Quarter level." Crystal Dynamics. Blood Omen 2 manual. pg10 (Eidos Interactive). (2002) Download.
- Umah: "I was in the heart of the main factory in the Industrial Quarter. Before the guards discovered me, I had found a huge central chamber that housed some kind of magic portal. This portal looked into a…place, the likes of which I had never seen before. And this portal was held open by a single source of magic, a stone set on a pedestal. Vorador, I believe it was the Nexus Stone." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Objective 3: Defeat Sebastian and recover the Nexus Stone. "The Nexus Stone is guarded by the vampire Sebastian. It was Sebastian who helped engineer Kain's defeat at the hands of the Sarafan Lord 200 years ago, and it is he who has been charged with preventing Kain from obtaining the stone now..." Prima Games. Prima's Official Strategy Guide to Blood Omen 2 (2002). Page 52-53. ISBN 0-7615-3774-0
- Kain VO: "The fiend that dogged my shadow showed himself at last, and in the light, I knew him. Another visage from my past..." // Kain: "Sebastian! It is you who have been following me." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Sebastian: "And how long it took you discover it. My master sent me, to prevent your meddling further. And now you must die." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Kain: "Your master knows his days are numbered. I might have spared your life by asking that you join me, but I learned that lesson two hundred years ago. You arranged the ambush that destroyed my army. You sold yourself to our enemy." // Sebastian: "I dealt the blow that cost you the war. Glorious, was it not? So many killed, so quickly. And all my doing." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Sebastian: "Did you think I would serve, while you ruled Nosgoth? You, and not I? The Sarafan Lord knows how to value me. I am to rule by his side, and achieve what you never could." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- "Boss Strategies: Sebastian" Prima Games. Prima's Official Strategy Guide to Blood Omen 2(2002). Page 5. ISBN 0-7615-3774-0
- Sebastian: "Jon, raise the dais!" Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Sebastian: "We will die together, Kain!" Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Sebastian: "The Nexus Stone's portal leads to an ancient Device, deep underground, that will spell your destruction, Kain. A new reign will begin in Nosgoth." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Kain: "Tell me of the Nexus Stone, and this portal. What is its purpose here? Speak, and I will spare your life."// Sebastian: (Laughs and coughs)"Come, Kain. You lie in your throat and we both know it. You are going to kill me."//Kain: "Indulge me then, before you die." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Sebastian: "I'll tell you, so that I may see your face when you learn – you are powerless – you cannot win – your death is inevitable. The Nexus Stone's portal leads to an ancient Device, deep underground, that will spell your destruction, Kain. A new reign will begin in Nosgoth."//Kain: "What is the purpose of this device? How will it serve the Sarafan Lord?"//Sebastian: "Alas, he has not entrusted me with that knowledge. But soon, everyone will know it. His plans are even now coming into fruition."//Kain: "Where is the device? Where under the earth?"//Sebastian: "It lies beneath Meridian. Seek for it, if you will. I die happy in the knowledge that all your efforts will be wasted." Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- "When the traitor is dead, you will absorb his Dark Gift and take the Nexus Stone." Prima Games. Prima's Official Strategy Guide to Blood Omen 2(2002).Page 53.ISBN 0-7615-3774-0
- Kain: "Oh Sebastian…Our destiny could have been glorious. The land was ours for the taking. History would have been rewritten in our image. But not everyone shared my vision. And now, your time is up. Your death will only make me stronger. I hope that knowledge comforts you, in your grave." (Kain takes the Berserk ability from Sebastian, then approaches the Nexus Stone. He rips it from its housing. The Portal suddenly closes, ripping machinery and starting a chain reaction of explosions. The room begins to fall apart around him. Kain runs towards the window, and leaps out as the room explodes. Everything goes black.) Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Early Dark Gifts at The Lost Worlds (by Ben Lincoln)
- Sebastian Page at Dark Chronicle (by Ardeth Silvereni).