The four flashlight housings affect the way the light is scattered The concave variants attempt to scatter the light more evenly across the crystal while the hole and flat variants sends most of the light though the tip. You only need one. 

The flashlight I used: https://www.amazon.com/gp/product/B0814MDZKP

Wrap painter's tape around flashlight until the housing and pylon slides on with friction. 

Superglue the crystal onto the housing. 

Superglue chain to sides of pylon.

Mine glows in the dark by using a clear resin and blue glow in the dark powder. 

Changes from previous models: 

https://cults3d.com/en/3d-model/fashion/print-in-place-chains-up-to-18-meters

Rearranged to fit on my print bed. 

https://www.thingiverse.com/thing:1177951

Used only the crystal, modified to fit flashlight. 

https://cults3d.com/en/3d-model/game/starcraft-protoss-pylon

Used only the pylon shielding. Changed position for pendant.