It's an 8th ed. Blood Knight only banner - you can't take it on Hexwraiths. The Vampire Counts FAQs doesn't have any clarification on this, but I think you can treat "ranged attacks" literally - i.e. anything with a range - so that would include magic missiles and direct damage spells. It wouldn't include vortexes, I think, as those don't have a range to them (and the damage is coming from the centre of the vortex not from the caster).
I tend to take it all the time on by Blood Knights, as I've already spent so damned much on them (points and £££s) that I want to keep them alive(ish) for as long as possible - and a 2+ armour save just doesn't stand up to much in the way of ranged attacks.
a 2+ armour save just doesn't stand up to much in the way of ranged attacks.
I assume you're talking about war machines and the like, because I know my meager Empire Archers, Handgunners, and Crossbowmen have some serious trouble punching through armor like that! Now Bolt Throwers on the other hand...
Anything with Strength 4 or armour piercing is a concern to them - but even a unit of say 30 High Elf archers will probably take one out in a volley. When your cavalry cost 50 points a model (so you're rarely fielding more than 5), you just can't afford to be losing any before you get to combat.