Almex87 I think you meant he couldn't be a Gen 2, especially since he hasnt commited Diablerie, unless of-course she was a forth child of Caine and he forgot about her, or she is Lilith as she in the main mythos got her power from Caine, and that was before the other three and she was never shown as killed off.
2nd Gen he'd be one of the strongest Vampires in existence, and that his sire would have to have somehow been one of the three vampires of myth from the book of Nod, 4th gen is more powerful than 99% of vampires.
It went Caine/Lilith (Depending on which mythos within the vamps, then the 1st gen, who all died all three from memory in their mythical first civilisation, then the 2nd gen who are all in torpor until Gehenna, then the strongest of those possibly concious, the top leadership awake among each clan etc, probably includes 3rd and 4th gen in that category, then their childer, and down the tree to whereever any particular vampire fits, if she was a Gen 2 shes an antideluvian and almost every vampire would kill themselves just to avoid her.
If you really thought about it then each Gen 2 and lower would be one higher as Gen 1 and 2 were both directly from Caine in the stories.
Is it based 100% on WOD, No, however many of us can see that most of the content so far still fits into it, Dev can do what they like as its their game, their story etc, but in WOD Gen does relate to blood potency, so while you do have a few paths to increase your potency besides Diablerie, most of the potency a character might have will relate to that of their Gen.