well for instance i drop a bio for new one so do get keep the jutsus i lerned using that bio and post it new one or will i have to start all over again
but if you train your kekke genkai like say you have a sasuke bio and you've trained it up to 3T and you drop him for an itachi bio or a custom uchiha bio. You still keep your 3T and sharingan genjutsu you've learned.