My first thought was how Symbiotes have the power to to copy abilities from others and in some cases even improve them, also called "genetic memory".
So the idea was to go to Soul Land verse (preferably thee first one cause thats the only one that i kinda of know the starting story of until Xiao Wu gets discovered. Never got past that in the original novels, and fanfics never live to that point before being dropped.) and using the Symbiote to get the bloodline of the spirit beasts there. But then i realized that it would not work and would probably get dropped cause of the power systems not matching and I dont really have a solid idea of how to incorporate spirit rings and the other usual stuff so thats scrapped.
Then i thought more broadly about cultivation worlds in general and their obsession with bloodline and remembered reading a couple of fanfics where the mc uses alchemy and formations to get the bloodlines of wild beasts like a flame tiger or an ice wolf etc... to bolster his combat power and also affinity with the elements. And thats where i can see the Symbiote being used to gather bloodlines. The mc can also be forced in to siding with evil cultivators because of his looks when he goes full Symboite suit, which makes it easier for him to get more risky bloodlines that can have major defects, but Symbiotes can filter those parts out, although they might need multiple bloodlines that improve different aspects to make a "proper" bloodline without defects, kinda like Library of the Heavens Path, but for bloodlines instead of martial techniques. This way the Symbiote handles only refining bloodlines and giving power ups while being in the suit, however the mc still has to cultivate to advance.
However here is the problem there is almost no novel that writers will be willing to write about with this trope in mind cause imo the hardest thing to write about are op stories as it is hard to keep the mc's power level in check while also writing a ff that is longer than 100 chapters, cause after that most stories just give up cause of the repetition and no new thing to do. The closest story i found that can make this work is Super Gene cause that novel is already about... u guessed it GENES. And even then (a non authors opinion) I think Super Gene's 3.5k chapters will be shortened to just 300 chapters if lucky cause the ff doesnt need to do world building that the original had to do and the ff mc will not have to go though all the hardships that the original mc has gone thru.
The only solution see to this is an original story with brand new world and brand new challenges for the mc (even though this will most probably be an op mc story.). The only things that can spice up the story is romance, harem and new stuff to keep the mc busy while he is power leveling.
I WILL BE EDITING AND UPDATING THIS SO WILL PROBABLY ADD A CHAPTER WITH THE TITLE LIKE "LAST UPDATED ON _____". SO KEEP ON CHECKING IN CAUSE OF UPDATES/CHANGES AND NEW IDEAS THAT I WILL ADD WILL THE HELP OF UR COMMENTS.