I must have have focused about 15+ event engrams to get more mementos. (Yes I have done the quest and yes I don't have in my inventory, I have applied it to a fusion rifle) And I have yet to receive a SECOND one, not a third or forth, a SECOND one. I have focused just for weapons, I have focused for Horror Story and nothing. What is the drop rate? you get one after 100 engrams? Because I am sorry this is ridiculous. It's just puts me off playing the even what so ever. I have finished the event card btw and almost guilded the title and still no SECOND memento.