First, Build the Wrath of the Ancients bow. Click this link on how to do that.
Second, Go on the death trap and on that location there is a wind compass in the top of the roof. Shot using your bow and the first part will reveal.
Third, there are three bonfire outside the map and you have to shot to light up. First location, near mule kick. Second location, on launch pad area. Third, between double tap and spawn area. Note: This can be done in any order.
Fourth, you need to go down where the pyramid are and activate the anti-gravity. Then, run the wall where you see a symbol like a wind without touching the ground. If you did this correctly, you will hear a chime.
Fifth, three electric base. This bases has to fill up with zombie soul that take for about 6 to 10 zombies. First location, Clock Tower. Its under the spiral staircase. Second location, launch pad area. Its in front of the teleporter machine. Third, above Double Tap between build-able table and launch pad. Note: This can be done in any order and you can use gun or any of your choice. Once you filled up with zombie souls, point and aim then press hold action button to suck up the electricity true your bow. Will hold it, you need to go to one of the bonfire then release it. If you did that correctly, you will hear a chime.
Last, Bring this arrow below and place it on the box with a wind and lightning symbol. This box is located on the pyramid. Kill zombie near until you hear a chime. Then, place you Wrath of the Ancient Bow and your lightning bow is ready to use.