About Death Seeker

I learned looking in some sites, that for creating the tournesol i need to sell, beyond other things, 6 death seekers to the bazaar. How can i get 6 death seekers? The only way i know to get death seekers is to kill that vampire, but it only gives me 3 death seekers, and i still need 3 more; i tried to save a game with the deathseekers on my inventary, but sadly looks like ingedients cant be saved, so, still remains the problem, how to get 6 death seekers in a single game, and still, another one for shinra's quest. So, anyone could help me? I would apreciate any help. Thanks.

You can periodically return to the tomb to get more.

Oh nice to know thx