Adafruit has shared plenty of DIY 3D printing projects in the past. This 3D Printed Halo Energy Sword is quite special though. It has NeoPixel LEDs inside the blades that connect to an Adafruit Feather BLE 32u4 micro-controller. You can use your smartphone to change the animation or color of the LEDs.
To complete this project, you are going to need a 2000 mAh battery, NeoPixel strips, a 3D printer, a soldering iron, and a few other parts and tools. The above video covers more on this cool sword.