Here's the a link to my previous post on this Collab.
PAD Skyozora with the information on the evolution to some of the cards in Chinese. astalotte with the translations in a PAD subreddit post.
The best card in the Collab REM is still Echidna Rococo as a sub but overall, I don't think there is much incentive to roll if you're non-IAP, except perhaps to get a REM card for collection, even with the addition of 4 skill-up cards available in the collab dungeon: Echidna Rococo, Black Zeus, Heraclodin and Shaman Ra.
I've never used the silver egg rolls I got previously: Hera Maria and Shaman Ra. I have, on the other hand, used the yamaP card to cover dark on a Hathor or Light Kali team and even managed to max skilled him with king gold dragons. His ultimate evolution leader skill is hilarious and I will probably farm an extra copy for that.
Update: GameWith and Game8's card ratings for the Collab REM cards in Japanese.
