Going over the non-Tenshi things that have been mentioned recently and adding things as I think of them,
-Adjust PAR to have a more substantial effect against higher SPD targets
-Increase the damage on Aya's spell card Wind God's Fan.
-Adjust the effect of the sub item Magic Sword "Chaos". Presently, it creates some imbalance between ATK and MAG characters.
-Adjust the effect of the sub item Scourge. Presently, it is weaker than the other items that are created using the Iron Man's Headband material item, such as Tupsimati.
-Reduce the power of Parsee's spell card Jealousy of the Kind and Lovely and make its condition for use easier to meet. Improve the damage of Midnight Anathema Ritual.
-Reduce the delay of Tokiko's spell cards The Count of Monte Cristo's Vengeance, Musketeer d'Artagnan's Recklessness, and The Future of Non-von Neumann Processors when not under the effect of Reading. Adjust the effect of the Awakening skill Tokiko's Thick Book Martial Arts to grant an ATK and DEF buff when not under the effect of Reading, and to grant a MAG and MND buff when under the effect of Reading. Add a MAG increasing effect to the skill Victim of Reimu and Marisa's Brutality.
-Adjust the effect of Shou's skill Bishamonten's Rage to be stronger and easier to activate. Adjust Aura of Justice's counter consumption to be more useful. Buff Dazzling Gold.
-Change Kokoro's Mask mechanic to be able to select masks when switching. Having to Concentrate multiple times in a row to change masks is too restrictive. Buff The Man of Qi Worries About the Earth.
-Regarding synergy skills such as Tenshi's Girl of Bhava-agra and Keine's With Mokou, there is a significant loss in damage if the player does not activate the skill, limiting character choices. Please adjust these characters so that they are stronger by themselves.
-Increase the damage of Youmu's spell card Slash of Eternity, and reduce the delay. Increase the damage of Slash Clearing the Six Senses.
Regarding Kokoro specifically, the only thing that comes to mind that makes her masks more usable is to have her Awakening grant spell cards that force a specific mask. Also, earlier I said I wanted Akyuu's Awakening spell card Miare's Great Knowledge to maintain the same effect as Protecting Art of Wisdom, but I think that this would be imbalanced (both for the game and for Akyuu's Protecting Art of Wisdom, which has worse delay and a higher MP cost) and that there would likely need to be some kind of compensation for it, such as increasing the delay or decreasing the Boost effect. It would be better to simply fix the bug and leave the spell card working as it was intended to.
Also, for Gambler, I think that adjusting the "increase damage done and taken" skill to have the "consume HP to increase damage" skill idea's effect is better than outright adding a new skill. By keeping Gambler at two skills, it's easier to balance, as there's less risk involved in the possibility of players getting too much damage by stacking all of its skills.
For Hina, it occurred to me that Two-Way Curse is a lot more difficult to activate on her than it should be because of Spinning More Than Usual, and the proposed adjustments I had in mind would have made it impossible to use Two-Way Curse and Spinning More Than Usual, because it would cover every status effect besides SHK and DTH. Because of that, I think Spinning More Than Usual should keep the status effect on Hina instead of removing it, and maybe negate the negative effects.
There were some other things but I lost track of them, I'll remember them later.
Ah yeah, one of them was to change Aspiration Surge's element from MYS to something else, in order to provide more coverage for MAG attackers. Not only do a lot of MAG attackers have MYS element spell cards, the basic attack command is MYS element for them, and Sorcerer powers it up pretty nicely. Although Aspiration Surge is still stronger than the powered up Magic Attack, I think it would be more useful if Aspiration Surge was a different element from MYS, such as SPI. In order to avoid redundancy with Archmage's spell cards, the only options are FIR, NTR, PHY, and SPI. PHY wouldn't make sense, and I think it shouldn't be FIR because of Explosive Flame Sword being its counterpart, so that leaves NTR or SPI. Of the two, SPI seems the best fit.
Example of Youmu's performance (spoilers): https://www.youtube.com/watch?v=-EnElwzSIxE&t=20m0s (still kinda overshadowed by Nitori though)
Regarding
, I'd like to see how Akyuu w/ Dragon God's Power handles it. I've been going all in on SPD for support due to Power of the Child of Miare's resurrection effect, but doing the same for offense, combining Super Incantation with a powerful spell card and Akyuu's excellent base MP + MP recovery...man, that should be something fun to try out.
For the run itself, I was initially thinking "wow Nitori really does need nerfing, look at how well she competes with Youmu at max Asura's Blood!", but then it occurred to me that Nitori has Magic Sword "Chaos", so her damage would probably be more reasonable without it. A small nerf should still be sufficient.
EDIT: Scratch the "make Tenshi and Keine better solo". I did a quick damage check for World Creation Press on Tenshi, with max buffs on everything a 20% ATK/MAG increase from Girl of Bhava-agra would be only 12% more damage compared to 28% as it currently is, although I think my DEF assumptions are too low at this point in the game, still using 1m. Regardless, my concern here is that by buffing Tenshi and nerfing Girl of Bhava-agra, Iku would become less effective at increasing Tenshi's damage than most damage increasing passives. I think it's better to have her more reliant on Iku specifically.