Crap crap crap. If atmosphere then made it to the home screen of Horizon, what possible traces could it have left?Fusee handles emuMMC slightly differently than Hekate in that it is managed by the emuMMC.ini file. If you do not have one, which I am assuming is the case, then Fusee booted CFW on your sysMMC. And there is no way to restore emuMMC to the sysMMC. You need to restore a clean NAND dump to revert the changes made to the sysMMC
Also, is there a chance that an ini could've pointed fusee to the emuMMC by default? I was using the default files that came with Kosmos.