Just how powerful Tenshi becomes remains to be seen (especially since there are many other very powerful NAT nukes such as Suwako and Yuuka), but at least she probably won't be the sitting duck she used to be. I still see her as a sort of niche option for certain bosses, but she probably went from "only bring her if you absolutely need Hisou Sword" to "Bring her against just about any NAT weak boss, as well as any boss requiring Iku's presence"
Not bad, though given how Alice is a rather frail, highly evasive mage, I don't think it'll change much for her viability.
It's also worth noting that, along with making Tenshi a truly viable attacker (She has really good formulas on her attacks- she just only had remotely viable ATK if Iku was out) she also gets up to +30% more def/mnd/spd and an even bigger base HP boost. She could be a REALLY bulky attacker.
It's worth mentioning awhile back, Tenshi's attacks got a stealth buff; her single-target NTR debuffs ATK and the all-target debuffs MAG and SPD. She's also not just a NTR attacker; SPI-ele Sword of Hisou is also strong apart from just the buff clearing. If you use Iku full-time you could totally run Tenshi as a bulky attacker now, I think. Weakness is a thing, but that's what subclasses are for (Although she'd definitely excel more on NTR/SPI/FIR weak bosses, she can still manage fine for triggering PHYS/WND/CLD- empower normal attack, puncturing thrust, samidare slash; you're only out of luck for MYS and DRK unless you lulz and sub archmage PURELY to hit weakness a few times)
Also, Alice... really isn't frail? Her HP isn't -great-, but it's -definitely- not on the low end, and her DEF is the same (13.6 and 7.8) and she has a very solid 10.6 in mind, in addition to her silly evasion. This heavy regen just further solidifies Alice as most definitely a bulky mage. Just give her DEF/Affinity boost and and Second HP Boost or something. She could make great use of a First Aid Kit now, for that matter. If someone with heavy max HP had an ability like that (recover a third of lost HP) they'd be immortal, but on the likes of Alice it's still nifty as heck; I've seen what it can do on Yukari.
What's this ability?
All the other buffs sound very nice too, albeit not as gamechanging probably. I'm a bit puzzled about the increase in Maxlvl for all those offensive spells - why those chars and not others? Only time will tell.
Black/White Reversal swaps whether Shikieiki's moves use Attack or Magic. So, if the boss resists Spirit or Dark or has major def/mnd, you can swap your build without having to change out what stat Shikieiki is built for; this also makes it slightly easier to use her because she can easily afford one concentration in a boss to swap to single-target Judgment, from the randoms build where she probably wants to be using her MAG all-targets. Throwing on a fairly large boost (Wait, that's even a little better than Grand Incantation) makes the ability truly interesting instead of just a convenience. Although it's a bit awkward since it swaps her element and whether she ignores defenses or not, it's interesting.
As for the attacks... it's an awkward way of increasing their power (Since it only really takes effect quite far into the game), but the reason for those characters and not others is pretty clearly (in most cases) that they are weaker characters. Youmu was still sort of garbage until her corridor awakening, but this is effectively a (rather expensive...) 20% buff to all her damage. Mystia also seriously needed it, and it makes offense Sanae more viable.
...of note is that I ran the numbers, and Sanae's spirit attack is now even stronger than lv5 Start of Heavenly Demise (if SoHD is on someone else and not receiving Sanae's SPI booster, that is). It factors like 1.6x as much MND though, of course. If you sub Sorc, Moses' Miracle also turns into a 307% MAG - 100% MND attack (factoring ONLY the extra levels- so I'm comparing a 5/9 moses to the 1/5 formula on the wiki). Sanae's MAG is a little on the lower end but those formulas, her moderate bulk, and side-support add up into a pretty solid character... and then her corridor makes her pump the entire front row's MP which is pretty sweet. If you use the whole moriya team, her bulk actually gets pretty dang nice and that MAG isn't on the low end anymore, making her totally competitive.
Actually, Moriya team is starting to look -really- nice. Sanae was sort of a weak link as other buff options came up (although byakuren was nerfed enough sanae can sorta compete), but she's getting more towards being a competitive offense option, Kanako is definitely a top contender (corridor gives her Majesty+ for 9% buffs a turn and she gets +50% dmg -25% recieved, so, UH), and Suwako becomes potentially the best glass cannon in the game (competing with Marisa and Flan). Malice Cannon also got nicer since Alice is even more compelling to use.
TBH I'm sort of tempted to run moriya team now, but only after I can afford to awaken at least 2/3 of them, so pretty lategame. I was already considering swapping in Suwako, and Kanako's awakening is lip-biting goodness.
Yuugi's knockout and phenomenon were already previously buffed, and now it's buffed AGAIN, so she's seriously turning into a juggernaut >.> And Remi could seriously use that buff on Vampiric Attack. She's starting to look more like an actually worthwhile bulky attacker, granted I totally would only use her in an SDM team, she's starting to look like a worthwhile use of slot in said team. 11% buffs each turn she uses a single-target attack- if you sub Monk that 15% is, with a strategist or other buff maintainer out, enough to maintain permanent 100%. (Or, she has enough buffs to afford subbing any of Warrior/Murakamo/Swordmaster/Monk to hit weakness)
And Shou is a bit more easily viable as an attacker. Her low attack until the rage counter manages to get rolling is a thing, even if the rage counter makes her potentially amazingly strong in a long boss fight.
