vampires life drain (Sanguinia mod nation) under water bless?

[militarist]

I have a question, maybe someone knows..
I'm trying vampires life drain (Sanguinia mod nation) under water bless.
Vampire has "rapire, life drain" written as a weapon.
Is it a life draining rapire, or life drain is a spell he casts after hitting rapire? I think that it's two separated weapons, just not sure.
What happens with it in case of water blessing?
If it's not using "life drain" because it's treated as a spell (though there could be a difference in game mechanics, as casting a spell and using a spell as weapon (Rleh), who can be given orders "fire" to use his native spell).

The next part of question is not related to vampires, mostly to forgable life draining weapon.
How would work water blessed unit with life draining weapon? Would it lifedrain both hits or only first?