InfoAh, yes. Lord Revan, the menace of Chapter 4. He is a force to be reckoned with, with 4 stages, each increasing in difficulty!
Lord Revan's basic attacks are summoning minions (equally as willing to kill you) and shooting his bow. Healers also spawn throughout the boss room, so make sure to kill those! At the first stage, he only utilizes his basic attacks, which still hurt. Afterward, his abilities become more and more frequent, along with dealing more damage. He may shoot beams of magic at you. Be sure to raise your shield, or your armor is going to take a beating. Finally, when his health becomes low enough, he harnesses the power of the Camlann, and routinely releases energy, knocking you back. Very far back. At this stage, try and use ranged weapons, and fend off the minions.