This trick only will work for one Pumpking, the purpose of having more than 1 is to have a better chance of getting it. First, get a Pumpking, Wasteland, Dark Energy, Castle of Dark Illusions, all in your hand, then put down Pumpking in defence, and Wasteland, at your next turn you put down Castle of Dark Illusions and equip it with Dark Energy bringing it's Defence up to 2230. over the next 4 turns your Pumpking will end up with 3200 ATK and 3400 DEF. Wait until you get both Castle of Dark Illusions and Dark Energy in your hand,equip Pumpking with them, then put down Castle of Dark Illusions, and equip it with Dark Energy.

Then 4 turns later, your Pumpking will have 4400 ATK and 4600 DEF. Then get the last Castle of Dark Illusions and Dark Energy. Put them down to pump up Pumpking to 5600 ATK and 5800 DEF. Then get the Hane Hanes, and put one Castle back each turn and put them back on the field. This will take about 19 turns at least but after that your Pumpking will have 9200 ATK and 9400 DEF. After equiping Pumpking with the crystals and swords, he will have 11,300 ATK and 11,500 DEF. No matter what monster your opponent puts down, its just 2 turns and they're gone. Not even the Five god dragon with 5000 ATK and 5000 DEF can stand against your Pumpking, when you attack the FGD, your opponents life points are down by 6300 life points.

NOTE: You don't have to drag this all the way, you can stop at any time you like. You can also add in a Witch's Apprentice to increase your Pumpking's power infinitely.