Get into a battle, then Right Click. Keep doing this until you get to the Blood Sprit or Shadow Reaper. Then, die. When you get to the "Defeated" screen, Right Click and select "Back". Repeat this until you hear the victory music. You will get 700 experience points.
Easy skills points
Go to the person that is sitting down next to a table, close to the door that tells you to complete the human gateway. Talk to him and he give you a ring. Go to the left until you see the moon. Press [Space] and you will earn a skill point. If you want more, save the game. Select "Restart" at the bottom right corner. Select "Start", choose the blue ninja, and go to any portal. Do not talk to the man until you die with the blue ninja. Load the game, then talk to the man again and repeat the trick.
Rare items
Choose your desired character, then save the game. Select the blue ninja, then go to the human gates. Right Click, then click Forward until you are battling the following enemies: Shaman, Mountain Naga, Semi Demon, Flesh Fiend, or Fallen Guardian. Then die. When you see the "Defeated" appear, click "Load", then go to the training. Click "Easy" when you are battling a training ward. Right Click then keep clicking "Forward" until you see the word "Victory". You will get 75 experience points and a rare item.