Well, most of my picks weren’t really “hyped” in the usual sense of the word, as it was more about the Waifu factor rather than their gameplay usefulness that had people gushing about them, but I’d say practically everything I pulled in the summer gachas aside of Summer Umu fits the bill.
-Punch Saint: Not useful for farming, very narrow and double-edged niche (we don’t really have any MC bosses outside of BB in the CCC event, while zerkers hit her just as hard as she hits them, negating her only advantage as a Ruler). If only her anti-trait buff was against Demonic enemies instead of just Demons, she would be much more generally useful.
-Maid Alter: She is competing with Ridertoki in the same niche, and she isn’t doing too great. The only reason I even Ascended her to stage three was because I ran out of space to store all the embers from the lottery and had to feed them to someone.
-Summer Nobu: I have never even used her, partly because she is new, but mostly because I have so many other ST zerkers she has to compete with, meaning that I likely won’t use her in the future either. Well, except maybe if I run into something where her Anti-Divine NP would give her an edge. We’ll see.
-Saber Fran: Yes, she is cute, but she serves pretty much the same role as Okita, and I barely use her anymore. Speaking of which…
-Okita: I remember that when she came out, everyone was hyped because she was the best ST saber in the game. Unfortunately for her, a couple of weeks later I pulled two copies of Bride Umu, making her mostly redundant. Hopefully Skadi will help her a little, but as of now, I usually take Umu, an AOE 4* saber and a support caster to deal with Lancer nodes, with Okita collecting dust in a corner.
-Herc: Let me be honest here: I understand his niche as the “last man standing”, and he is really good at what he does. It’s just that, aside of some extraordinary occasions, like when the RNG decides to screw with me and ruins a run with random crits or enemies spamming batteries and the NP-ing me off-turn, he never actually gets to come out. Because of this, his main use is for solo-cheesing… which I can do just by borrowing a friend’s Herc.
Also, while she is a welfare servant, Shiki is worth a mention:
-Shiki: People consider her to be one of the best Assassins, but I think that is just a testament of how weak an/or inconsistent most of the assassins are. While I use her a lot, I never found her to be a game-changer like Ridertoki, and the fact that she needs a ton of bones is just the final nail in the coffin.