You can't get things like Eldritch Decay because Uber Elder Fragments are a boss drop, but you can get cards like Last Hope and Sambodhi's Vow because Mortal Fragments aren't exclusive to boss drops.
You can't get things like Eldritch Decay because Uber Elder Fragments are a boss drop, but you can get cards like Last Hope and Sambodhi's Vow because Mortal Fragments aren't exclusive to boss drops.