Set up the moves Leaf Blade or Leaf Storm (I prefer Leaf Storm and recommend you to use it because its stronger) and go do Lavender Tower. If you cant two hit K.O. the first pokemon, Cubone, then set up the moves softboiled and Leaf Blade or Leaf Storm. Use Leaf Blade or Leaf Storm and defeat the first Pokemon. If your HP is lower than half, than use softboiled until you have full HP and keep using Leaf Storm until you defeat the second Pokemon, DarkMarowak. If your HP is lowered under half again, use softboiled and then Leaf Storm.