Q. In a situation where a Vampire automatically kills an enemy
model or causes multiple wounds, and he has the Red Fury power,
does he gain an additional attack for every Wound remaining on the
slain model's profile? (p83)
A. Yes.

Lets say he is in a challenge. Kills the champion or chacater that made the challenge. Can he still use his "new" attacks" to kill rank-and-file? Hope not becuse he is still in a challenge.

Can the vampire choose to use one attack at the moment to kill off characters with Frostblade. Lets say 3 characters in base-to-base contact. First rolling to hit one character, and misses. Then use second attack on same character and hit and kill, and gets 3 extra attacks becuse of the Frost Blade / Red Fury combo. Keep trying to hit next character etc.

OR are you "forced" to divide attacks befor rolling to see if you kill he characters. I hope it works like this.

Thanks for all help.