hi hi, let's see what can I find.
[General]
Not nitpicking about your difficulty names but wouldn't you just rename Oni to Inner Oni, and Lite Oni to Oni? This is by far more common to use.
[Oni]
00:51:495 (271,272,273,274,275) - actually I wanted to suggest swaping 00:51:829 (274,275) - since (274) is a more significant sound but I noticed that your kat follow is mainly for the drum beat, and k k is a silly idea for that case. However, you shouldn't use kkd but kdd instead. The sound at 00:51:495 - is rather short than long so kdd emphasize it better.
Very clean difficulty, really enjoyable to play.
[Lite Oni]
00:35:495 (120,121,122,123) - what about ddd k? the kkk sounds pretty weak since you previously used k at 00:35:329 - . Another alternative would be kdd but I am unsure how do you feel about a multi-color triplet here. Following that change, you may also change 00:35:829 - to kat.
[Muzukashii]
01:17:662 (276,277,278,279) - Should that be k ddd? This parts works very similar like 01:16:329 (272,273,274,275) - , I don't find you should change it here.
01:18:995 (280,281,282,283,284) - since you're going well with the background music, you could change this part to k kkddk; 01:19:829 - has an existing beat (it's quite calm however, like 01:19:662 - ) and should be mapped with d. 01:18:995 (280) - sounds strange as d, the piano is too light as you could use d properly imo.
01:27:829 (309) - I would prefer if you move the note to 01:27:995 - , the 1/2 rhythm is pretty weird and feels forced.
01:30:495 (318) - for the consistency I would stick with the background music and less for the vocals, remove this note if you applied above.
[Futsuu]
00:30:662 (45) - since the beat at 00:31:329 - due drums is imo more significant, I would prefer to emphasize this sound. Also, change the note to d afterwards.
00:42:995 - 00:45:329 - It's a weird decision to change your rhythm in a Futsuu so drastically, imo. I would keep it like that: https://derpovic.s-ul.eu/xAN8QIAt.png but it's your decision.
01:27:329 - 01:27:995 - While you mainly focused on the background music, it's odd you follow the vocals here. I mean, you can do that but I find the pattern are pretty flow-breaking. Try that instead: https://derpovic.s-ul.eu/j0AgL5Um.png
01:29:995 - 01:30:662 - either https://derpovic.s-ul.eu/y4r5H8qW.png with dd kk or https://derpovic.s-ul.eu/42bZ1d0l.png with dd k could be used here, both works very well since dd kk supports vocal and background and dd k has a bigger focus on vocal mapping.
01:41:329 (209,210) - You use kd on 01:42:662 (212,213) - for the same emphasis, I would do this with 01:41:329 - 01:41:495 - too. You may even use kdd but I think kd is better.
[Kantan]
00:21:662 - from here you could use oo as rhythm: https://derpovic.s-ul.eu/9ktM88si.png this adds some more variety since the music is "stronger" from here and worth to map denser. It's also closer to the Futsuu Difficulty.
00:26:995 (16,17,18,19) - (coming from 01:34:162 (93,94,95) - because I forgot to mention) - 1/2 should be avoided as much as possible, there are ways to avoid it, try this for example: https://derpovic.s-ul.eu/T1JMS28W.png
01:04:329 - here too, you may not want to use it before (means at 00:53:662 - ) since it boosts your SR up but eh.. SR barely means something. The Difficulty itself is easy, even with that rhythm since it's very simple to follow.
01:34:162 (93,94,95) - I wouldn't use 1/2 in that Kantan at all, use this rhythm instead: https://derpovic.s-ul.eu/lqsvbAnF.png You could make them to Big Kats, fits also well.
01:44:329 (98,99,100,101) - Same case, https://derpovic.s-ul.eu/XUWYHRPM.png this mainly focus on the Background Music tho.
edit: I've noticed that your thread had some double posts. I made a little clean-up so it's clearer now.
[General]
Not nitpicking about your difficulty names but wouldn't you just rename Oni to Inner Oni, and Lite Oni to Oni? This is by far more common to use.
[Oni]
00:51:495 (271,272,273,274,275) - actually I wanted to suggest swaping 00:51:829 (274,275) - since (274) is a more significant sound but I noticed that your kat follow is mainly for the drum beat, and k k is a silly idea for that case. However, you shouldn't use kkd but kdd instead. The sound at 00:51:495 - is rather short than long so kdd emphasize it better.
Very clean difficulty, really enjoyable to play.
[Lite Oni]
00:35:495 (120,121,122,123) - what about ddd k? the kkk sounds pretty weak since you previously used k at 00:35:329 - . Another alternative would be kdd but I am unsure how do you feel about a multi-color triplet here. Following that change, you may also change 00:35:829 - to kat.
[Muzukashii]
01:17:662 (276,277,278,279) - Should that be k ddd? This parts works very similar like 01:16:329 (272,273,274,275) - , I don't find you should change it here.
01:18:995 (280,281,282,283,284) - since you're going well with the background music, you could change this part to k kkddk; 01:19:829 - has an existing beat (it's quite calm however, like 01:19:662 - ) and should be mapped with d. 01:18:995 (280) - sounds strange as d, the piano is too light as you could use d properly imo.
01:27:829 (309) - I would prefer if you move the note to 01:27:995 - , the 1/2 rhythm is pretty weird and feels forced.
01:30:495 (318) - for the consistency I would stick with the background music and less for the vocals, remove this note if you applied above.
[Futsuu]
00:30:662 (45) - since the beat at 00:31:329 - due drums is imo more significant, I would prefer to emphasize this sound. Also, change the note to d afterwards.
00:42:995 - 00:45:329 - It's a weird decision to change your rhythm in a Futsuu so drastically, imo. I would keep it like that: https://derpovic.s-ul.eu/xAN8QIAt.png but it's your decision.
01:27:329 - 01:27:995 - While you mainly focused on the background music, it's odd you follow the vocals here. I mean, you can do that but I find the pattern are pretty flow-breaking. Try that instead: https://derpovic.s-ul.eu/j0AgL5Um.png
01:29:995 - 01:30:662 - either https://derpovic.s-ul.eu/y4r5H8qW.png with dd kk or https://derpovic.s-ul.eu/42bZ1d0l.png with dd k could be used here, both works very well since dd kk supports vocal and background and dd k has a bigger focus on vocal mapping.
01:41:329 (209,210) - You use kd on 01:42:662 (212,213) - for the same emphasis, I would do this with 01:41:329 - 01:41:495 - too. You may even use kdd but I think kd is better.
[Kantan]
00:21:662 - from here you could use oo as rhythm: https://derpovic.s-ul.eu/9ktM88si.png this adds some more variety since the music is "stronger" from here and worth to map denser. It's also closer to the Futsuu Difficulty.
00:26:995 (16,17,18,19) - (coming from 01:34:162 (93,94,95) - because I forgot to mention) - 1/2 should be avoided as much as possible, there are ways to avoid it, try this for example: https://derpovic.s-ul.eu/T1JMS28W.png
01:04:329 - here too, you may not want to use it before (means at 00:53:662 - ) since it boosts your SR up but eh.. SR barely means something. The Difficulty itself is easy, even with that rhythm since it's very simple to follow.
01:34:162 (93,94,95) - I wouldn't use 1/2 in that Kantan at all, use this rhythm instead: https://derpovic.s-ul.eu/lqsvbAnF.png You could make them to Big Kats, fits also well.
01:44:329 (98,99,100,101) - Same case, https://derpovic.s-ul.eu/XUWYHRPM.png this mainly focus on the Background Music tho.
edit: I've noticed that your thread had some double posts. I made a little clean-up so it's clearer now.