fx, red velvet or aespa: most experimental?

after snsd, sm is determined to be experimental with their girl groups. out of these three, which do you consider most experimental?

I think they are all experimental in slightly different ways.

Fx from a random concept and genre of music kind of way.

Red Velvet from a dual concept and a kookie/creepy sort of vibe to their music. That said, I think their songs are usually really coherent individually as are their albums.

Aespa from a never seen before futuristic and metaversal concept extending beyond the music, and the crazy switch ups within each song.

idk but zimzalabim is the worst song in that list