New cards and card buffs translation: http://puzzledragonx.com/en/news.asp?nid=457
GameWith card ratings: http://パズドラ.gamewith.jp/article/show/11338
Game8 card ratings: https://game8.jp/archives/23935
The 3 new gold collab cards are generally improved versions of existing PAD cards: Athena, Red Sonia and Kirin, gaining skill bind resists, haste or delay to their skills. The most important new addition is the co-op stats awakening.
Those above 3 cards will be useful for co-op and as the roll out for those awakenings are slow, these are expensive "early access" cards for you to help farm co-op for MP like in the highest difficulty Zaerog Infinity co-op dungeon. (Colored preDra are drops on that difficulty)
I actually rolled silver egg Kai (http://puzzledragonx.com/en/monster.asp?n=1978) in one of the returns of the Collab and kept him for a long time. He is like a poor man's Loki, with great typing and good awakenings for leaders like Hathor, Halloween Kali and even Asmodeus Another to boost their multiplier. However, the long cooldown and my unwillingness to skill up with pii means the team needs to stall for it to be up. Somehow, I ended up never using him on my Hathor team as I have other options for dark and recently sold for MP as I cleared most of my non-Pantheon God cards!
My single roll for today's collab return was Asmodeus Another! I have enough leaders for now but I'll be keeping her around as she has a board change which is almost always useful and it's nice to have an alternative to Hathor. Hopefully, I can hold onto her until she gets an alternative evolution!
Edit:
minpuzz.com is discussing the possibility of using Shinra Sacred Demon God Ark as a sub for Yomi Dragon, in Japanese: http://minpuzz.com/blog-entry-9161.html
http://puzzledragonx.com/en/monster.asp?n=1975
I tried to run the page through Google translate and still didn't understand much of it although the God typing, good awakenings and AS do fit into Yomi Dragon teams but probably only if you do not have the main Yomi Dragon REM subs.