[reubiedoo]

I mean it is counted like a signature spell surely?

 

[Lord Sven Kittyclaw]

It clearly states in its description that it may be cast multiple times.

 

[Cheese meister]

i would use summon undead horde ove inovcation now as it's not using alot more dice if your safe dice casting invocation but allows you to raise 3d6 wounds

 

[Tim/Steve]

I mean it is counted like a signature spell surely?

Depends what you are asking... but yes either way. Multiple vampires can have it, and they can each cast it multiple times each round.