Lord Kardok is the general that struck down Dan in the story at the start of the game, being found in the Zarok's lair level. The whole level is a fight with Zarok / his minions, and his general Kardok that has 3 phases.

The first phase has you use good lighting (gotten from a chest at the start of the room) to heal your skeletons allies while they fight Zarok's minions. The skeletons colors range from green to red showing how much health they have left, every time you heal them it takes health from you. Keep them healthy (and use the rejuvenation fountain in the corner to keep yourself alive) until they win. Once one of the enemy ones dies it's basically over as then 2 will attack the same enemy and so on. The second phase summons a large horse rider enemy that has a shield at almost all times. When it charges at you the shield goes away and you can damage him. This fight consists of dodging him and then hitting him right after, any Longbow is the best for this. The third and final phase has you against Zarok himself, just turned into a weird dragon thing. Similar to the last phase, Zarok is invulnerable 99% of the time. You need to dodge his attacks (best done by holding  to shield run) until he stands up on his hind legs. Once he does shoot him with any variation of the Longbow and repeat. Once the fight is over the ending cutscene will play and you will unlock this trophy.