Even when he was being creepy by any normal person’s standards (lurking in the shadows, hovering over his mother, and using that manipulative tone with his dad) Danny still smiled and acted like a happy little puppy anytime Vlad was around.
This is explicitly shown in the dance hall, where Danny is bored out of his wits and scowling at everyone, when Vlad comes along and puts a hand on his back, and suddenly the world is smiley again.
It goes on further to explain why Danny seemed so stricken when he found out Plasmius and Masters were one in the same; First, that the man he’d been attracted to was a big evil jerk that had just beat the crap out of him and tried to kill his dad;
But second and more importantly, that even though they were the only two halfas in existence, Vlad still wanted Danny to give up everything; because Danny as he was was not enough.
So of course he picked his family because, well… he’s Danny. Even a perfect sexy half ghost can’t stop him from wanting to protect them with all his heart. That’s just his character.
And if Vlad had paid attention to that aspect of his personality for two damn seconds (HE USES HIS POWERS FOR GOOD. OBVIOUSLY THIS KID HAS A HERO COMPLEX. DUH.) then maybe he’d have realized that if he hadn’t given Danny any ultimatum and apologized for kicking his ass, Danny would’ve been pretty willing to accept him with open arms.
Canon Vlad was STUPID.