We are many, you are one. Ermac is perfect for the player who wants high risk with high reward in Mortal Kombat X.
The Master of Souls variation is great for mixing up air juggles that end in high damage combos. Spectral makes Ermac airborne and grants him access to quick special attacks. Mystic is great for pushing opponents away to the corner.
Ermac is not for beginners since one wrong move could lead to tragic results.