Dios is a sidescrolling action adventure game that has some strange behaviour with its weapons. Each character can get three weapons, and for all of them the first and third weapon's shots pass through enemies. Each character's second weapon does not, making them universally a downgrade from the default for no apparent reason. By changing a single byte at address #3814 from #C0 to #C9, the second weapon will pass through enemies like the others, making it a worthwhile upgrade.
Now that a dump of the CD version of Dios is available, I was able to compare the two. As it turns out, the CD version behaves exactly the opposite, so the second weapon pierces but the first and third do not. The subroutine is the same in both versions, just at a slightly different offset. Making the same change would make it so that none of the weapons pierce, but changing #3826 from #C0 to #00 instead will have the intended effect.
The disk image of Tug of War that is available online may be a bad dump, or it may be broken in the original, but regardless there is a bug which freezes the game in an endless loop after beating the last boss. By changing a single byte at address #3999 from #FE to #00, the ending of the game can be viewed normally.
All disk images I could find online for the PC-98 version of Cluju appear to have the same problem where map data is missing or corrupted on disk B for the town in the desert area. On entering the broken screen, it loads data from cylinder 2C, head 0, sector 1 of disk B (disk params at 0800:7ad2), which just contains the byte "40" repeated. It is either pointing to the wrong sector or the sector is corrupt. 0800:a69c is the routine called to load the data from disk and the map tiles are loaded to b400:0000.
Once the PC-88 version was acquired and dumped, I was able to compare the two. While the code is of course different, some of the data is formatted the same, including the map data missing for this screen. I was able to enter the screen on the PC-88 version in M88, dump the RAM (screen data loaded to C000-E000), and copy that into 2C/0/01-10 and 2D/0/01-10 on Disk B of the PC-98 version.
One of the shops in that part of the game was not working properly, charging 101 for any item despite the price listed. For some reason, just the item shop was having issues so I compared it to the weapon shops code. The weapon shop code loads the pointer for the cost to DX and then calls the same subroutines as the item shop, but the item shop loads the pointer to DI, then pushes DI and pops DX right before calling the subroutine that checks price. However, the subroutine called right before that by both shops trashes DI so it always ends up being 0B4E. I just changed the item shop to load to DX and removed the code to copy from DI, so it functions just like the other shops.