I don´t watch kdramas, but I have heard that Exo´s D.O. is a good actor? however, that´s probably not the correct answer to your question :D.
I´d say maybe Lucas could be good at some comedic sketches, SNL style?
I´d say maybe Shinee´s Key could be good? I hope Minho is good, I still want to watch his film ♥, but I feel like Key is such a diva on the surface, but someone really kind and humble on the inside and he´d pull some acting out of his sleeve pretty easily.