Should I evolve this 15/15/1 level 30 Gastly?
During last year's Halloween event I only caught one Gastly because they just didn't spawn where I live, but this year they are spawning decently and thanks to double candy and Pinap berries, I have over 400 candies already. My only Gengar is level 14 because I walked a Gastly that I hatched back when I was level 12, so I really want some hard hitting Gengars for Alakazam and Mewtwo and anything else that I can use it for in the future. I have caught a few good Gastly today and got a 98% one last night and there's plenty of time left, but should I evolve this one too? I know it's terrible for such a glass cannon to have a 1 for stamina, but 15 attack and 15 defense, plus being level 30 already, makes it very tempting to evolve. Would this be a waste of candy?

Answers
Against Psycho cut/focus blast Alakazam solo raid, Gengar is undisputedly the MVP. Outside of that, he is also useful for the other alakazam raids and the gengar raid itself.
However, 1 Stamina on Gengar sounds really painful...I usually evolve level 30 pokemon anyway, but the 1 stamina in this case...I don't know.