Only way I know of is buying it from a DBD Hacking Service on this website or, you can edit your savefile and there should be lines in it that say if you have the teachables for that character unlocked, just change those.
Is there a way to unlock teachable perks quickly without having to lvl up characters 1 by 1? Not with savefile since I have legacy in all the characters more than a year ago and I don't want to modify it
Only way I know of is buying it from a DBD Hacking Service on this website or, you can edit your savefile and there should be lines in it that say if you have the teachables for that character unlocked, just change those.
There is only way: editing your save file and make it either look like you leveled those characters up and unlocked them normally or make it look like you bought them from the shrine.
I wouldn't recommend getting teachables for people you don't own, devs can see what perks you bought from shrine with shards