[quote=@Unoedipal]
<Snipped quote by hatakekuro>

You're giving it more credit than it deserves. 
[/quote]

I'm analyzing this NP and really, I feel like I'm not. The weaknesses that I see are as follows: 

1: Huge mana consumption on both the master and servant

2. Uncontrollable 

3. Requires a servant of the age of man or a modern day human to kill that, which even then is hardly a weakness because is strong enough on its own right to take down high leveled servants of the age of man and a human killing it? I think very few masters can bring it down.