1st Encounter: Hold and when he attacks and your Spider Sense triggers, hit and any direction to avoid it. Now press and keep attacking him. He will eventually jump up on a pole and spiked traps will trigger. You will have to jump and hit to get knock Kraven off the pole. His attacks will get more aggresive but the fight will be the same. You will have to do two fist fight sequences as well within this fight.
Final Encounter: This fight is a lot like the first one, just keep dodging and attacking when possible. Kraven will be more difficult to hit, but there won't be any interuptions in this fight. Just keep dodging and attacking. He will sometimes jump on the pillars, so knock him off when he does.