Arc: 1 Khyber
Arc 2: Malware
However Malware is dead, and Khyber returned in Arc 4 and is still active so I think Kyber is the bigger threat currently. I think it would be cool if he teamed up with Vilgax.
Omniverse doesn't seem to have a tight single villain/villainous group like in other series/seasons, but Khyber seems to be the closest to that.
The main villain is neither. Arc 7 and 8, wait for it.
Arc 2: Malware
However Malware is dead, and Khyber returned in Arc 4 and is still active so I think Kyber is the bigger threat currently. I think it would be cool if he teamed up with Vilgax.
vilgax and khyber? AWESOME PAIR