>>42516764Depends on your use.
Skarm has spikes, rocks, and Taunt, Corvi is the better body, and has U-Turn to escape magnet pull.
If you just want the bulky pivot, Corvi is your go to. If you want the support and field control, you go Skarm. If you don't care, and already have something else on hazard duty, Corvi's better body and ability to not just fucking die to Magnezone is better than anything else Skarm brings.
I think Corvi has a weak edge over Skarm, but this edge is very much negotiable based on the needs of your team.