who is the most powerful person darwin can adapt to?

who?

He adapted to Hela, who is a Hell Lord...

Darwin converted to energy before too so idk. it would have to be someone like Proteus or some crazy reality warper im thinking.

his power is to survive not to fight so to speak so BFR might be an option for most of the heavy hitters

Now you're playing with power

https://comicnewbies.files.wordpress.com/2013/09/darwin-vs-the-hulk.jpg