So I thought I'd try and experiment with region changing a bit, and I don't understand what's going wrong here. I now have both a US region 3DS XL and Japanese region 3DS LL, both on exploitable firmware. And they both have the same size NAND (I know there are two types) First, I tried using rxTools - decrypted the partitions, then swapped contents and injected emuNAND partitions from the US system on my Japanese system. Tried to boot emuNAND, got blackscreened ("bricked") Next, I took a sysNAND dump, generated a NAND FAT16 xorpad, copied both from both systems on my computer. Used 3DS FAT16 Tool to extract the partition from the NAND dump, xored both. xored the US decrypted FAT16 with Japanese xorpad, re-injected, used emuNAND Tool to inject. Still bricked. What I don't get is why it causes a brick. I thought the xorpad was the main difference between NANDs on different systems - otherwise it's just a folder with files in it. I would understand if the firm0/firm1 weren't compatible, but both systems are XLs so I can assume that isn't the case. Any other ideas?