Actually , since you have XCDVIL you have XC is 90, D is 500 minus the preceding 90 is 410, VI is 6, L is 50 minus the preceding 6 is 44. 410 + 44 = 454, which is OK anyway because the Number of the Beast is actually 616, not 666.

What it really is is:

Deus Conteret eX VIro, DCXVI, God grinds out of man.