Odessy/Dark star/Cosmic lore question

So i just read the dark star lore and the cosmic lore and the odyssey lore as well and i have a question, if kayn can theoretically kill Rhasst and take his power would that make him on par with the comics characters that keep the dark star characters at bay and if so could other beings do the same? lets face it there are quite a few characters that if given the chance to be in certain skin lines stand a good chance and overpowering a dark star. e.g Teemo (i'm serious) ,Vladimir , bard (not sure why he would want to seeing as he can basically do what he wants anyway), Xerath, and most notably viktor and swain. (i say viktor since he has little to no emotion and would probably see through a darks stars lies and see its true intentions and hook it up to a machine to get the power rather than let it effect his mind). Also if kayn is capable of doing so (not saying he would ever be able to since he is a bit too delusional to see Rhassts true intentionsas classic kayn anyway) then why can't the cosmic skins?

i imagine thresh would not care to much tbh i mean he gets to die and whoever kills him gets the universe as his or her own sandbox, just imagine all of the planets populated by only bronze 5 -3lp emote spamming yasuo's you could make, it would be heaven.

Now this question relies on the fact that from what i the lore gives us for a dark star to enter another universe it has to enter it as some kind of artefact or weapon and get somebody else to "let them out". Also i hate to burst the dark stars bubble but the multiverse is literally infinite so have fun trying to eat everything while more and more universes come into existence faster than thresh can feed them to you whilst also dealing with the exact copies of you that you would inevitably meet who would also try to eat you.

P.S would be nice if Necrit made a vid on this concept and some other fan question but i am doubtful he will ever see this (if you do give that Yasuo sock puppet a cookie i wanna see it again) give us yasock.