My dude, do you have any idea how much halfway decent art is? Especially when you need like seven different transformations for each portrait. Basic professional quality illustrations and the rights to use them in a commercial product cost thousands of dollars per picture, and you'd have to find someone okay with their work being used in a game like this. And if you commission an amateur to save money, they might disappear off the face of the earth or stop taking commissions a month from now, so enjoy having wildly different, clashing art styles for every portrait after that.
You'd have to hire the artist full-time to avoid that, and again, that wouldn't be cheap. But if you don't believe me, go talk to a commission artist and see what they quote you to make a portrait pack for you.
You'd have to hire the artist full-time to avoid that, and again, that wouldn't be cheap. But if you don't believe me, go talk to a commission artist and see what they quote you to make a portrait pack for you.