The fact that Miquella is still there and probably alive, while there is a sizeable area behind the egg which is completely empty save for a platform that ends abruptly mid-air, pretty much screams DLC.
How does the lord of blood deal with something that gains blood every attack
Tbf, if the Boss VS Boss videos are anything to go by, Mohg actually stands a pretty good chance against Malenia. The only reason she wins most of the time is because his NIHIL attack doesn't work on her for some reason.