If we are talking about "growing" our collection (because there's no more exclusive characters), the update for character relics is really good, and make the prize fights more interesting (for the new players or players that are growing, for the others it's only to search the keys).
If we are talking about new players or players that are growing or exploring all the modes of the game like origin stories the update is bad, because they generally have more the feeling of "I need this character to move along of this mode" or "I want this specific character because I like/love, etc.", so the new "specific" character relic rate it's only to dissapoint the new players, there's no guarantee about getting the character you really want or else, and yeah, you can say that you won't get anymore a bunch of the same and useless character but you took the risk from the start (with this I reffer to the older versions of the game). Yeah, you can improve or raise your collection with other characters, but I feel these reason isn't enough to change the rate (Think about characters that don't like the player, for example I have Beowulf and Double characters but I don't like them, I feel dissapointed when I got one from Valentine relic for example). So I have concluded the "specific" character relic doesn't have a reason to exist (with the exception of the new characters that will come in future updates).
P.S.: If I make a mistake about writing or comment structure I want to apologize, my english's knowledge is low.