What might be helpful is to buy the Boss RV20. It can add an octave in female or male, do 3rds, 5ths, in male or female, or multi voice up to 6 + the usual delay , reverb, and more.
It has pitch correction, ( i think you can do hard or soft but apparently hard sounds like a Cher voice ). It does more than i've stated as well. Great bit of kit
https://www.amazon.co.uk/Boss-VE-20-Vocal-Performer-Multi-Effects/dp/B002W0Z8DU