2018-10-05 : If Attendant of Vraska’s power was negative, you don’t lose or gain life.

2018-10-05 : If you don’t control a Vraska planeswalker as Attendant of Vraska’s triggered ability resolves, possibly because Vraska left the battlefield at the same time as Attendant of Vraska, you won’t gain life.

2018-10-05 : The amount of life gained is equal to Attendant of Vraska’s power as it last existed on the battlefield.