Ashurei said:
And I quote..
"However, models with the Vampiric, Ethereal, or Large Target special rules can never regain more than 1 wound per successful casting. Wounds gained are distributes as described in Resurrecting fallen Warriors (page 26.).
Page 26: Some magic spells and items can resurrect fallen warriors in an Undead unit by restoring a number of Wound's worth of models to the unit. Unless specifically stated otherwise, spells and magic items that restore lost Wounds cannot heal Characters or their mounts. Of a character has joined a unit, only the unit will recover lost wounds. "
Notice : Cairn Wraiths and Tomb Banshee's are considered characters (Troop Type: Infantry (Character)). this is the same as all Lords and Hero's.
Black Knights : Special rules : Frenzy, Undead, Vampiric.
The vampiric rule will supersede the fact that it is an undead unit. It doesn;t matter what interpretation you choose to use as a BS way to get around it, the rules clearly state that if you have the Vampiric rule, you can only ever regain one wound. Ever. There is really no negotiation or room for interpretation there.
Vampiric is a subset of Undead. All vampires are undead, and so cause fear, can only hold as a reaction, immune to psych, crumble, etc, but obviously not all undead models are vampiric. Its been that way, so your statement doesn't really further the discussion.
What you are missing is the wording. Invocation specifies units (and goes into the types of units), while the qualifications and restrictions refer to models. Models make up units, and models can be units if on their own, but a the wording is very clear that models with the rule Vampire only gain one wound back from casting and units of cavalry targeted by Invocation gain 1+Caster Level.
Simple (lol) RAW vs RAI, but the thing is, none of us know what is intended. We know what the last book told us, but none of that really holds up anymore for a variety of reasons, the least of which being a completely different author wrote this new book.
So, while its nice to say "it wasn't intended to be this way," until the FAQ comes out, we don't know what they were intending because they obviously weren't reading it very closely themselves.
Now, in the interest of nipping some arguments and complaints on both sides, go with what we think is intended. I won't say its fair, or right, or whatever, but in the interest of fun and not coming across as a tool (since, that's what these arguments devolve into), if you use Blood Knights in friendly games, just roll with it. Wait for the FAQ, and then do what that says. Its either gonna be awesome or expected.