The reasons behind no item, no UT's, no ninpo rules are easy to understand. You know that UT's and ninpo basically let Ryu kill enemies without even fighting them, while items can cover a lot of mistakes from the player. Though, I don't think people ever tried to add no Izuna drop rules. Also, I have to say that even if the rule was no Izuna drops and similar (basically no aerial drops) I also avoid using any form of air to air move/combo, except for some enemies that could fly in the sky, like Marbus for example.
The reson behind these additional rules is the following: in any NG game, the interesting stuff happens on the ground. When you launch yourself in the air with an enemy, and start hitting him, you are almost invulnerable, so you can kill that enemy in full safety, while completely ignoring defence. So, since this game is so easy compared to the other ones I played in the series, I wanted to try this rule.
So, I'll just highlight the parts that gave me the most trouble.
- Momiji: her chapter has been hard because I wasn't used to her, but after a lot of practice I learned to use her and I think it's a good character. I learn a lot about defence with her. I tried to replay this chapter in chapter challenge and I got to last part without much trouble. I still struggle against vang elfs though, the most random enemies in the game for me.
- Armadillo: final boss of the flying fortress Dedalus chapter. It's the only boss that I still can't figure out. The first phae is easy but the second phase is incredibly annoying. So, got to the first phase, I just tried to survive until he started spitting fire, when I got close to him and unleashed a furious DPS against his leg. It's probably the only thing in the game I can't figure out.
- Zedonius + gaja's: in this fight I just had to use Izuna drops, I couldn't find any other solid strat, I was just becoming insane. And it has been incredibly difficult even using Izuna. But really cool fight, very challenging, gave me a big sense of accomplishment.
- chapter 14 last gauntlet: the last gautlet after Genshin fight on Mt.Fuji. Very challenging at first, undead ninjas + purple ninjas + mages. I learned a lot of stuff there, it has been really fun, but frustrating at times so I had to take many breaks form it. Though it has been extremely worth because there I learned a lot about the game, and especially about running attacks, which are very underused in this game I think. Though, some weapons have VERY strong running attacks, and there are ways to set them up safely.
- Centaurs: not really challenging but I'm kinda happy of the few things I discovered about them, because I've always wondered if they couldn've been killed by just hitting them on the ground. I don't know if it would work in vanilla, but in this game they can be fought and killed on the ground. The scythe is probably the best weapon at fighting them because it has big range.
I don't think I had much more troubles for the rest of the game. It took me weeks, but everything was manageable.
The weapons I used most have been:
- dual swords: especially for the second half of the game. The most versatile weapon imo. People seems to like 360T, but I'm more of a fan of running T, running S, ->ST, ->SS. Running T or ->ST (same identical move) have the highest delimb rate of the game I think, that move seems also to have really good i-frames and almost no recovery, it can go straight into OT and if you want you can also shuriken cancel. Running S or ->SS (same move) has probably the same delimb rate, but can hit multiple enemies, at the cost of less i-frames, more recovery and no shuriken cancellability. TTTT good for bosses, first two hits can be cancelled. Has also some other minor things that can be useful.
- talons: SSSS string is safe and has good delimb rate, the first three hits can be cancelled into shuriken and the fourth turns enemies on their back giving Ryu frame advantage. The slide has i-frames and stun enemies but I've been grabbed out of it sometimes. SSST (hold) is a kick grab that makes Ryu fully invincible and can behead. Running TTT is really good for delimb rate, and if the enemy gets delimbed by one of the first two hits Ryu goes immediately into OT, otherwise he goes into the kick grab for i-frame safety. Majestic.
- tonfa: heavenly justice cancels, also SSTTT which can't be cancelled but has high delimb rate. The most fun weapon of the game, I think a lot can be done with this weapon, the player who master it becomes a god. I also think there are some fun juggle combos that can be done by alternating ->ST cancel and ST hold cancel, but I didn't try cause I'm not very interested in this aspect of the game.
- kusarigama: LOL. Did you ever try this weapon? Really? It doesn't make sense. You toss the chain and as soon as you grab the enemy you get i-frames and delimb him. Tossing the chain is slow, but it can be done from distance, and can be set up in different ways: windpath, S->T, SS->T, 360TS, OL SS. So it's all about chain toss setups. At first is trickybecause the chain is a bit slow, but after a couple of minutes you get the hang of the weapon and you just stop using it because it breaks the game even more than using Izuna drops and similar. If it wasn't enough, it has a ground combo that goes into an i-frames grab. It has other moves that are less effective than in vanilla, because of the lower delimb rates of this game, but the weapon is totally broken imo.
- Eclipse Scythe: the glorious weapon of Volf, ruler of storms, king of the lycans. I really like Volf as a character, don't ask why, I just like him. His weapon looks cool, I didn't use it much but it proved to be extremely useful against certain enemies, to the point I wanted to mention it as one of the most important weapons of the run. I'm talking especially about centaurs and marionettes, but I also used it against Volf himself during his second fight, and it was really really good at fighting him. I still don't know much about the weapon, I mostly used TTT. The first two hits of the combo are very safe if you block after them. This weapon have some grabs, so it probably has i-frames during them. You can also go into a grab from the flying swallow. So I just suspect this is an OP weapon.
I don't like the Dragon Sword and even the True Dragon sword. They seem to be tailored for setting up Izuna as fast as possible, they can even launch enemies from the counter. Didn't use the Lunar and the Flails much, though I'm interested in both. The flails seem to have a good delimb rate on ->T at level 2. When you upgrade them at level 3, that attack lose its delimb rate in exchange for juggle properties, and can be followed by a self launcher move. So it really depend on the playstyle you want to use. I would probably keep them at level 2, and accept lower damage in exchange for high delimb rate, and I would use a different weapon for bosses.