You can make a clean lfcs_b using movable.sed, I'm terrible at explaining so some 3dbrew reading could probably help. (also note: plaintext OTP also contains lfcs)
It probably has something to do with the mod, you can try a ctrtransfer if you want but I'm gonna assume it's the mod.
Here are some details if anyone else wants to help:
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Error type: generic
Process ID: 15
Process name: menu
Process title...
Try doing a safemode update (A+R+L+Up(DPad) while booting), if that doesn't work consider yeeting all spotpass data (ctrnand/data/<id0>/sysdata/00010034)
Actually your system isn't "hardbricked", grab arm9loaderhax.bin from here and boot.firm from here and put both the files on your sd root. After that insert your sd card into your 3ds and try powering on
Congrats! you just wasted your money. Follow this guide to get cfw on your 3ds (ninjhax is an old outdated and unnecessary entrypoint) Also emunands are useless nowadays because there's no risks involved in running cfw on sysnand