Alright, two things: one of the ISOs I have for the game don't work with any patch. The other one (the one I'm playing now), has a problem in a few chapters, where it crashes the game before loading the map. I can circumvent this by opening the unpatched ISO and loading the map there, then saving the game with the map loaded and open it on the patched version, but this means all the units on the map have their HP lowered and the enemy placement and weapons they hold are all unpatched (I even have some mages holding C rank tomes they can't use with their D rank skills on 1-7 because of this).
Second, let's talk skills: I haven't played too much of the patch yet, but I've seen you're doing a pretty fine job mixing and matching skills and giving more availability to them. Leo having Disarm, Fiona with that mega Blessing and Meg with Butcher are my favorites! Inherit skills like Canto and Shove not taking any Capacity are great additions too - they shouldn't even be skills in the first place, IS should have made them Class Skills, like FE9, where they exist outside the Capacity field. However, I believe we can do better here:
-Vantage: In the Japanese version, IS did a very stupid thing - they removed the 100% activation rate for Resolve, Wrath and Vantage, making those skills unreliable and, in some cases, a liability, since you're taking up space that be used by another skill that activates 100% of the time or doesn't need to put your character in harm's way to be useful, not to mention removing them from character that come equipped would do no good, since reattaching them would take up room in the Capacity wheel. The Western releases made Resolve and Wrath back to guarantee activation under 30% HP, but Vantage still got a Speed% activation rate. If it were me, I'd put Vantage back to 100%.
-Nihil and Mastery Skills: Nihil is a very, very stupid skill. You are basically required to have it to defeat the last boss, but the lack of enemies possessing combat-related skills in this game made it a pretty useless skill to have for the majority of the campaign, until it was suddenly required without prior warning. Even worse, the characters that have said skill were likely left behind, and now you have to take on the damage from Ashera's aura.
However, I understand why the developers came up with said skill. Mastery Skills are basically a OHKO, multiplying strength by 5, lowering defenses to 0 and teabagging the enemy after it dies in one hit. Here's the problem, though - Mastery Skills should have never been that powerful! In FE9, Mastery Skills are a disappointment because they take up too much room in the Capacity wheel and most of them (Astra, Rend, Colossus, Deadeye, etc) are useless when compared to the Skills combination you can take. Wrath + Resolve will ALWAYS be more effective than Astra or Colossus. In order to make the mastery Skills more valuable, they cranked them up to eleven and locked them to 3rd tier, but when they realized they went too far, they gave every Endgame boss a Nihil, so every single skill you have is useless - this on the game that expanded upon the skill system from its predecessor. So, how would I fix it? Simple:
-Mastery Skills should be nerfed down, close to what FE9 did;
-Nihil should nullify either combat-related skills (like Adept or Vantage) or Mastery Skills
My reasoning for this is simple: in FE9, using a Mastery Skill meant choosing one character over another to have it, plus sacrificing all the space you had for two or more skills. With Mastery Skills being kinda disappointing (Save a few, like Sol, Aether and Lethality), you'd want to stay away from them. But in RD, Mastery Skills are locked to your character upon 2nd promotion, so you don't have a choice BUT to have them, so making them so powerful goes counter to their availability. You either make them OP but rare, or available to everyone but far more manageable. I'm taking the later route.
When it comes down to Nihil, my reasoning is that we already have a skill that negates every other skill in the game - Parity. And Parity does a much better job at it, since it needs to be activated by command and only work on the Player's Turn, giving you more control over the battle, but also negates your own bonuses. Nihil can negate everything on the enemy's side, but doesn't bring any negative effects to your side, making it too one-sided. If we nerf the Mastery Skills, Nihil can focus only on one set of skills to nullify while letting the unity suffer/benefit from everything else that affects combat, like support, terrain, etc.
Here's how I would have done the Mastery Skills:
Savage
Increases Strength by 25% and halves enemy’s Skill for one turn
(Skill/2)%
Wolf
0
Rend
Increases Strength by 25% and prevents enemy from moving for one turn
(Speed/2)%
Cat
0
Roar
Increases Strength by 25% and halves Enemy Movement
(Strength/2)%
Tiger, Lion
0
Ire
Reduces enemy's Defense/Resistance to 0
(Skill/2)%
Red Dragon, White Dragon, Black Dragon
0
Aether
Attacks twice consecutively, with the first hit having a Sol effect and the second hit having a Luna effect
(Skill/2)%
Vanguard
0
Astra
Attacks five times consecutively at half power
(Skill/2)%
Trueblade
0
Impale
Lowers Enemy Defense/Resistance by half
(Skill/2)%
Sentinel
0
Luna
Negates enemy’s Defense [but not Resistance]
(Skill/2)%
Marshall
0
Eclipse
Negates enemy’s Defense and Resistance
(Skill/2)%
Black Knight
0
Sol
User recovers HP equal to damage done to enemy
(Skill/2)%
Silver Knight, Gold Knight, Valkyrie
0
Flare
Negates Resistance and user recovers HP equal to damage done to enemy
(Skill/2)%
Archsage, Empress, Summoner
0
Corona
Negates Resistance and halves enemy’s Accuracy for one turn
(Skill/2)%
Saint, Light Priestess, Chancellor
0
Bane
Reduces enemy’s HP to 1 [Doesn’t work on certain enemies/Doesn't activate if the hit would have killed the enemy]
(Skill/2)%
Whisper
0
Lethality
Instantly KOs enemy [Doesn’t work on certain enemies]
(Skill/2)%
Assassin
0
Stun
Increases Damage by 25% and prevents enemy from moving for one turn
(Skill/2)%
Seraph Knight, Dragonlord, Queen
0
Deadeye
100% accuracy when activated, sends enemy to sleep for 1 turn
(Skill/2)%
Marksman
0
Colossus
Increases Strength by 50%
(Strength/2)%
Reaver
0
Tear
Increases Strength by 25% and halves enemy’s Speed for one turn
(Speed/2)%
Hawk, Raven
0
I feel like this would bring a much better balance to the overall game. No 3rd tier class would feel overpowered, Nihil and Mantle could play an important part in combat without making the Skill system null, Aurora could still be a threat without Nihil and/or Parity, and your character customization would still play a major role during combat. Personally, I would make Nihil negate non-Mastery Skills, but I guess it would take a lot of testing to see which style would fit better.
That's it for my contributions to this project, hope it helps amount to something. Have in mind that I'm still in Ch. 1-7, haven't fully explored the patch yet, but I feel like these changes would make both the base game and this patch much more interesting to play.