Article in English: The weather vane near the death ray contraption.  It's sticking out of the cone-shaped roof near the death ray.  Shoot the dragon symbol until it starts spinning around.  An arrow will pop out of the wall. After the arrow pops out of the wall, grab the arrow.  This starts a new upgrade quest. In order to complete the upgrade quest, you cannot pick up any new upgrade quest items. The three bonfire locations are as follows:  The first one is directly beside the clock tower outside the map. The next one is east to the KRM wall buy. The final one is at the rocket pad, with a bunch of sticks on top of a stone slab. This is the room with the pyramid plates and blue wind icons on the wall. Wait for the anti-gravity cycle to start and run across the five solid wind symbols on the wall.  You cannot touch the ground. If you touch the ground, you will need to wall run all the symbols again. You'll know you're finished if you hear a sound cue after hitting the final wind panel. If the pyramid is not turned on, the low gravity cycles will not occur.  To turn on the pyramid, stand on the 4 blue pyramid symbols in the undercroft. Kill zombies around the electric urns to fill them up with souls.  The locations of these urns are as follows:  In the small room above Double Tap.  In the lower courtyard, near the jump pad and build table. The final one is in the rocket pad near the teleporter. To charge your arrow, stand near a full urn and draw the arrow back like you are doing a power shot. Then shoot the bonfire with an electric charged arrow.  If you miss the shot, you will need to charge the arrow again. Go back to where you picked up the arrow.  You will see sparks in the spot you got the arrow.  Press and hold square if on PS4, or X if on XBOX to place your arrows in the sparks.  They will elevate up to the dragon weathervane.  Wait for the arrows to come back down where you can pick them up again. After you pick up the arrow from below the weathervane, take it back to the undercroft.  This is the room where you ran on...

Summary in Indonesian:
Tembak penunjuk arah angin (weathervane) naga. Ambil anak panah. Tembak 3 api unggun/tumpukan kayu di luar peta. Turunlah ke Ruang Tanpa Gravitasi (Undercroft). Berlarilah ke semua simbol di dinding. Isi guci di sekeliling peta. Tembak api unggun kembali dengan panah listrik. Dapatkan anak panah listrik dari titik baling-baling mata angin. Bawa anak panah ke Ruang Tanpa Gravitasi (Undercroft). Letakkan panah di dalam peti petir. Bunuh zombi. Letakkan busur panah di dalam kotak. Ambil busur.