Since I am interested in all things Gremory, I have been thinking about what the buffs mean.
First off, from what I've seen around, there is a common notion that one really wants about 10 row enhances and that, after that, you should look for OEs. I'm not sure why that is, but, if that is the case, the Gremory buff means that OEs are a more prized awakening than they were before. After the buff, there won't be a solid justification for DD Akechi on Gremory. The HP and bind clear are nice as well, but you need a lot of hearts for a bind clear and a cross. I feel like the bind clear just makes her a better cleric sub on other teams.
As for the leaderskill, Yomi dragon is the obvious choice. However, I doubt it is as clear a choice as everyone seems to think at this point, especially vs. Plum. While both are certainly strong inclusions, I have a suspicion that Plum may actually be a bit better overall, especially in multiples. In Yomi's favor, he's unbindable, has an OE, has an extra TE, an extra skill boost, and his active skill has more board impact. That's a lot of stuff. In Plum's favor, her active skill is two turns quicker to cool down, has a row, a TPA, and a Killer. While I'm not an expert, I have been playing Gremory for several weeks now and three hearts, three dark fixes most fixable boards. There are times where having an extra heart makes a huge difference, but a lot of the time if 3/3 wouldn't get it, neither would 4/4 (e.g. enemy changed the board). I also don't think the 2 turn CD difference can be understated either, especially on a haste active. My favorite feature of YomiDra is that he is unbindable, however, most binds aren't a large issue for Gremory (some of those 10 turn suckers though...). If anything, YomiDra is closer to A. Pandora, certainly not a bad thing, but usually not run in multiples. Plum occupies an important niche in that she is the fastest ideal orb maker with haste. YomiDra doesn't change that (even though he is fantastic). On the other hand, YomiDra is a capable leader on his own, which means there is added value outside of the Gremory team. Either way, this means I am likely waiting a while before making an MP purchase for Gremory.
I'm wondering who else this opens up. Off the top of my head, Eschamali is the OE queen, but she is saddled with a heartbreaking active. Awoken Haku also might have some use, but I'm not sure it is worth the trouble. I guess Dark Metatron fits, but additional spike and damage shield seem underwhelming.
Overall, I'm not sure that this actually changes much for Gremory. I would have likely preferred the original buff, as damage is underwhelming sometimes on non-AS turns. Just my two cents.