This collaboration is returning for the second time after quite some time and it'll be the first time I'll be taking part in it for the Japan version as I was on an old NA account the first time it appeared. This update wasn't very interesting for me as there don't seem to be any new cards while the old cards got minor changes in the form of buffs for active skill cool-downs and the gold eggs getting more awakenings but no changes in skills with the ultimate evolution.
The silver eggs mostly serve as low cost leaders, although I'm guessing it will be hard to find other people running the same ones. The most useful ones IMO are Melody and Kuromi with Melody making into green teams, like Osiris', because her active delays and enhance which is really useful, while Kuromi is a shield breaker for devil teams. The Gold cards mostly serve as leaders with Pompompurin also being used as a sub for his active skill enhance for light cards. Princess Valkitty, on the other hand, could pair with and/or use Cloud(s). I do not recall seeing her used as a sub most of the time probably because her delay is only 1 turn plus a lack of farmable skill-up card for her.
Following the trend of recent collaborations, there should be skill-up cards in the collab dungeon for the collab REM cards but none was announced so far. The dungeon is great for Fruit Dragon skill-ups and the rare invade Kittyn & Mimmyna is a good replacement for Idunn & Idunna for mono blue teams and also Yo & Siegfriend's team because she is balanced.
In conclusion, all the card artworks are really cute and if you are a Hello Kitty fan or just like cute things, you definitely don't want to miss this. I don't think there are a lot of useful or attractive cards in this so I'll probably just roll once.
