Are achievements supposed to carry over from character to character? Or do you need to complete the same achievement with each character. I noticed my in-game achievement screen with a new character shows all uncompleted while the achievements at the character selection screen are partially done?
Achievements are Account wide and are tied to your Battle.net account, not each individual character. So if you get an achievement for a HC character, then lose that character, you do not have to get that achievement again. Or if you Delete a character, you will not have to get the achievements for that character again.