My suffix is indeed abaft.
And matching, as on such a craft,
my prefix is in front indeed,
both of themselves bereft, pay heed!
My infix, but you need to mix,
is IVLIA to 666.
This whole my whole builds like a song
and you have used me all along.
Hint 1 (on prefix, infix and suffix overlapping):
These three parts do not overlap,
they fit exactly with no gap.
Hint 2 (on the wording):
The wording of the first four rows,
not for the rhyme alone I chose.
It's meant to set a certain flair,
from where to pick the pre-suf pair.
No word comes from the 'pay heed' part
It's there so that you take to heart
that once you have this pair of two
something is left with them to do.
Hint 3 (on 666):
"..., for it's the number of a man."
Hint 4 (on IVLIA):
Beware that you might find this dame
at first just by her younger name.
Make sure that if a hunch feels great
you thoroughly investigate.
Hint 5 (on the hints):
I did not rhyme just for applause,
but also for a certain cause.