he really raised the bar there,and like blana often says fally was one of his generation guys if not the guy at that point who had the strongest pool of ghost vocal writers(blana himself,his dad,fally's "nephew" lindalala gino bescherelle and co) until the matete crew arrived via heritier
imagine him in the dimension he is today performing ko ko ko with koffi
i want to say something about fally's singing but i hope i wont be misinterpreted,i have it on good authority that my guy sings one heeeelllll lot or used to sing a lot because it was helping him cope with the behind the scenes world,to absorb the stress,to avoid or dodge remorse and all that so unlike ferre as you said he might even be doing silence cures that much,barely talking for a whole week or more to keep the voice fresh like ferre does when he goes invisible
notice his mentor koffi got a similar "decline",these guys especially with being able to play guitar on their own at some point sang wayyyy too much in days and even the surgeries they had when their issues were already advanced could not save it