ok if this is a diamond x leo hybrid the fails would be:
mercury - 1hrs
air - 2hrs
genie - 8hrs
virgo - 8hrs
celestial - 9hrs
bat - 9hrs
music - 10hrs
coral - 10hrs
aquarius - 10hrs
pisces - 10hrs
water - 12hrs
mistmoth - 12hrs
iridescent - 12hrs
taurus - 12hrs
capricorn - 12hrs
scorpion - 12hrs
mist - 14hrs
cancer - 14hrs
patchwork - 14hrs
night elf - 14hrs (not sure if night elf is possible...)
gemini - 15hrs
aether - 16hrs
peacock - 18hrs
trickster - 18hrs
magic - 20hrs
sagittarius - 20hrs
leo - 21hrs
social - 21hrs
wizard - 22hrs
mindvolt - 22hrs
night - 23hrs (i'm not sure if this is a fail since i've never heard of anyone breeding a night with this)
dark angel - 23hrs
aries - 24hrs
black diamond - 24hrs
penumbra - 25hrs
libra - 27hrs
anubis - 40hrs
gold - 44hrs
astromancer - ??? hrs
that should be it, lol xD