Character splinters
I just watched This video by Space Coconut: https://www.youtube.com/watch?v=T1eMK1LvFI8
He brings up a good idea about how you should get splinters for characters you don't own to be able to do challenges.
Maybe when you select a challenge that involves a certain character or perk you don't have it gives you a splinter that will only leave your inventory when your done with that challenge.
Using the splinter will let you play that character with all 3 of their teachable perks at tier 1
Comments
If they did that, what would be the point of having a specific character to begin with?
That would be a great idea, plus it would get people a feel for the character and their teachables.