'Idiot! You are already dead, just enjoy your life before your last breath!'
She wasn't exactly wrong, because what the 'Blood Rose' fed upon was actually blood essence and not just normal blood.
In order to keep her growing at a steady rate, Eric would have to feed her at least one drop of blood essence, which was close to 0.01% of his vitality per day.
Even if he had some sort of great vitality recovering ability, he would still end up dying in a short time. Of course, that was valid for normal people.
What White Ghost didn't know was that Eric possessed a much pure Dragon bloodline than the flower itself, and one drop of his blood essence would be enough to drown the flower if he didn't dilute it.
In fact, the reason why his blood hadn't managed to go further than one day, was due to the fact that he fed the Blood Flower with his normal blood.