Each of the Regi Titans have their own shrine making use of the Braille Blocks which form a word that refers to one of the External Moves a pixelmon can use. Now here's where it gets a little tricky for the coders. The shrine block is coded so that it spawns a Regi, depending on whether in an ice, steel, or rock themed shrine, when the correct external move is used directly next to it. The shrine block will act almost like an observer block except instead of detecting block changes it will detect if a move is used.
If this is worth your time and actually feasible, I wouldn't mind building up a few shrine bases.