Wow thanks for the info, I'll be trying this, however this is my first time so I'm gonna post everything I'm going to do in case I mess up at some point and need some help.
First I got this info from the files I'll be swapping:
001A
22, 426 bytes
0003
18, 560 bytes
those are the 2 files I'm swapping.
The size should be smaller now. I was trying to repack using the kiwi.ds app but I am getting a 0KB file as a result
Update: The problem was because I use another unpacker, I decided to go with NDS Editor's unpacker and swapped the sequences, I also swapped the corresponding soundbanks and repacked. Game is playable but the sounds are really messed up, a backdash says ''akumajou dracula'' >_>
I believe this is because the resulting SDAT was a bit smaller, the new sseq file was smaller, but the new sbnk file was bigger
2nd Update:
I've been reading more of the topics you link about file swapping, so far I understand how you can make the game read another file, although it works on same size files. I thought I could simply add the new sseq and sbnk to the end of the sdat and just make the gama read those instead but if I add a file after tearing the SDAT apart, I don't know if reassembling is going to simply going to add the new files in the middle of the file and mess up the sounds.
I think it might be best to just alter the files so that they could mimic the originals in size, which means I will have to increase the sseq file size and decrease the sbnk but I don't know how to trim a file and if making those modifications is going to bring me further problems.
small mistake: sseq file is smaller, sbnk is ALSO smaller
The above is true when viewed with crystal tile, but on the windows file view the second bank is bigger
