Just one small question about Viktor's standart recommended item build

I mean...i might miss something but...why Is Morellonomicon a DEFENSIVE item choice? Someone enlighten me on that one... and how come luden's isn't even mentioned in his rec Build at all?

And incase that non-compromising random someone tells me i am just mad. no. I just played viktor myself and since he is the very first champ i bought i've always loved playing him and he's been my longest fellow, but i only tonight noticed his Build path's "defensive" category and it made me have wide question mark stuffed eyes.

anyone care to enlighten me?