108: 1+0+8=9
216: 2+1+6=9
666: 6+6+6=18 1+8=9
As the HPs have stated, 9 is the number of ending. Also, some thing interesting that I found is that in vortex based math, if you double the numbers 1-2-4-8-7-5 and reduce any sum that has more than one digit down to a single digit by adding the...