Continuing on from my comment, I have an interpretation of what I feel could be an answer, but given there are 3 of them I'm uncertain I'm even on the right track.
In my comment I postulated that the "slice" indicated division.
Working backwards from the assumption I multiplied 666 by 1-9 to determine 4-digit numbers that would satisfy the "slice my thigh" (between 3rd and 4th digits) and came up with four numbers: 1332, 2664, 3996, and 5328. Of those four numbers, the first 3 all have an interesting property to them.
When you "slice" their neck (1/3322, 2/6644, and 3/9966) they all result in 0.000301204... which is interesting and could be considered "epic".
When you "slice" their waist (13/322, 26/644, and 39/966) they all result in 0.04037 which is also surprising and may confirm (or make the "kill") to their significance.
And when you "slice" their thigh (1332/2, 2664/4, and 3996/6) they all equal 666.
Slicing all three (1/3/32/2, etc.) is overkill, and no longer keeps to the pattern.