you need to find healers you should find them in the temples or if you'r early in the brother hood you can talk to vicente vabitieri. once you spoke with any of them go to the acrane university and talk to raminus polus. then go to skingrad and talk to hal_lirurz to get the count to come.

follow your quest marker to drakelowe. her house is marked as trasspassing form a glitch so talk to her quick. now you need three empty grand soul gems they can be stolen. crayfish cave nornal and squandered mine the quest adds a grand soul gem to each place. and command for empty grand soul gems are 00015B8E for an easy way out.

ok so you made it. befor you get thos things talk to her befor you get them so you now how much to get. blood grass can be found in planes in obilvon, outside of broken gates. The Main Ingredient should all was have nightshade. homes in skingrad should have them in there basements and now blood of a Argonian so use the knife she gave you and stab any argonian. oh yea allmost forgot ashs of an powerful vampire no normal ashs wont do you need to kill hindrail in redwater slough. your allmost there now to get pass the quest braking bug. dont enter the basement at all or give her the stuff at 12 am or she will never get out now wait 24 hours and you have the potion. you can now choose to finish the quest or just ingore it