In Blood Omen 2, Marcus is encountered in a Boss Battle. The Boss fight takes place in Meridian Cathedral, when Kain is finally able to enter the building at the end of Chapter 4:The Upper City. Unlike fellow 'traitor vampire' Faustus, Marcus made himself known to Kain early in the level and much of Chapter 4: The Upper City ended up being a race between Marcus and Kain to reach the Bishop of Meridian (at the Bishop's Manor and Meridian Cathedral respectively).
When Kain returned to the Cathedral, he found Marcus had control of the Bishop of Meridian (using his Dark Gift - Charm). Kain threatened Marcus and participated in another short 'prelude' chase before Kain and Marcus fell through the roof of the Cathedral. Once Kain had 'cornered' Marcus in the Cathedral, the boss battle followed the usual '3 phase' pattern, seen throughout Blood Omen 2 bosses.
A brief chase following Marcus after he has fled from Kain; after Kain found Marcus in control of the Bishop of Meridian in the private chambers of the Cathedral, Kain and threatened Marcus, who fled out to the street. Kain gave chase, following up some ladders to the rooftops and onto the stained glass roof of Meridian Cathedral itself, which collapsed, trapping the two vampires in the Cathedral[Blood Omen 2].
A battle with Marcus in the lower levels of the Cathedral. Marcus becomes invisible, only 'appearing' to strike Kain with red attacks. Marcus invisibility made him incredibly difficult to strike, instead Kain had to use two levers hidden in alcoves in opposite sides of the Cathedral, which when activated, rang the Cathedral bells, apparently dazing and causing some pain to Marcus. Once Marcus was dazed Kain had a small window of opportunity to strike back with his own combo or Fury strike (before Marcus would respond with his own red attack). Kain could repeat this process (by alternating levers) until Marcus summoned two Sarafan Priests to cut the ropes to the bells and retreated to the upper level of the Cathedral.[Blood Omen 2].
Kain follows Marcus up some stairs to the upper level balconies, where Marcus summons more Sarafan Priests to attack Kain (these Sarafan Priests fire crossbows at Kain and do not drop weapons; they will also 'respawn' when killed). Marcus will run around the top level of the Cathedral; he can be targeted up close using Kain's claws, or from a distance using a Jump attack. As he runs around, he will also repeatedly pause on the edges of the circular balconies and can be attacked by targeting a well timed Jump attack across from balcony to balcony and following this up with close range attacks until Marcus flees; repeating the process as Marcus ran by. Frustrated Marcus will again begin to use his invisibility.[Blood Omen 2].
Marcus turns invisible and actively starts to seek out and attack Kain as he runs around (using yellow attacks -though his use of invisibility seems a little 'compromised' by his damage). Kain could use the grab-throw technique on one of the Sarafan Priests and throw them into the bells (causing Marcus to suffer the same effects as in Phase One) or continue to use the Jump attack and close quarters technique (used in Phase Two) and take advantage of Marcus' compromised invisibility.[Blood Omen 2].
- In the 'prelude' phase Marcus shows the ability to leap at least as far as Faustus' Jump Dark Gift allows Kain to, he also repeatedly demonstrates the 'gift' of invisibility throughout the rest of the boss battle[Blood Omen 2].
- In the 'prelude' phase Marcus also demonstrates behaviour similar to Sebastian when Kain met him in Chapter 3:The Lower City; in that despite the situation supposedly being a 'chase' situation, the antagonist character (Marcus and Sebastian respectively) does not actually attempt to run away, instead they merely retreat away to the next obstacle and wait for Kain to follow[Blood Omen 2].
- In Phase One, Marcus displays a similar weakness to that of events of Soul ReaverVampires[Soul Reaver] (including Turel's Defiance appearance[Defiance]) - a sensitivity to sound[Blood Omen 2]. Kain rings the bells of Meridian Cathedral, causing Marcus great pain - Kain himself seems to suffer no discomfort[Blood Omen 2] 
- At the end Phase Three, Marcus lands somewhat awkwardly on the Cathedral's altar (on the lower level), but it is not clear how he got there; the previous two phases were on the upper level and Marcus is not shown to fall from the top level, though this is presumably what happened[Blood Omen 2].
- The original scripts of Blood Omen 2 imply that it was originally planned that during Marcus' boss battle he would have attempted to Charm the Bishop of Meridian into walking through one of the Cathedral's stained glass windows and plunging to his death.[Blood Omen 2/Cut content]
- Marcus: "Another of the traitorous vampires working with the Sarafan. He can be found in the Upper City level. Beware his psychic abilities." Crystal Dynamics. Blood Omen 2 manual. pg10 (Eidos Interactive). (2002) Download.
- Marcus: "No matter. My mental power still allowed me to read your thoughts. You seek the Bishop of Meridian, do you not? He has some information that you require."//Kain: "Clever trick."//Marcus: "I will ensure that you never get that information.You may find the good Bishop, Kain, but when you do – he will be dead."//Kain: "Not if I reach him first –" Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Marcus: "You there! You are to conduct me to the Bishop’s manor on the instant."Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Vorador: "Kain, it is Vorador. You must reach the Bishop’s manor at the other end of the city. Only he can give you passage into the Seraphan Keep. The curfew has set in, so be careful on the streets. The guards are looking for anyone suspicious, and will attack you on sight."Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Kain: "Yes, you will. Tell me where to find the Bishop."//Butler: "I can't – I mean, I don't know –"//Kain: "Shall I ease your mind and tell you I am sent by Vorador for the vampire resistance? Or shall I simply tear out your throat and continue my search? I leave the decision to you."//Butler: "The Cathedral – he fled there. He thought he would be safe."Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Marcus: "You are too late, Kain. He is entirely in my power."//Kain: "Release him, and I may spare your life"//Marcus: "I hold the cards now, Kain. Surrender yourself to me, or I will kill him"//Kain: "What do I care for the life of some mortal? But the thought of killing you at last entices me. Tell me, Marcus. Do you truly believe you can stop me?"//Marcus: "Stay back! You cannot win. The Bishop will tell you nothing while he remains under my power. And you will never catch me!"Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Objective 2: Defeat Marcus to free the Bishop from his mind control. "The Bishop isn't going to be able to tell you anything in his current state of mind. Unless you defeat Marcus, the old man will remain forever silent." Prima Games. Prima's Official Strategy Guide to Blood Omen 2 (2002). Page 38-39. ISBN 0-7615-3774-0
- Boss Strategies: Marcus Prima Games. Prima's Official Strategy Guide to Blood Omen 2 (2002). Page 4. ISBN 0-7615-3774-0
- "After you deliver the final blow, you'll watch as Marcus lands unceremoniously upon the altar. Kain will approach and absorb the vampire's Dark Gift" Prima Games. Prima's Official Strategy Guide to Blood Omen 2(2002).Page 39.ISBN 0-7615-3774-0
- Marcus: "Damn you. Damn those bells! Ugh, my ears!" Crystal Dynamics. Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.
- Marcus at Dark Chronicle (by Ardeth Silvereni).