So I finally got around to experimenting with my Silver Surfer at different levels to see when he truly becomes scary. So first off, I think there are different levels of scary. One is just that he can help out in a match, which is around 4 covers, but only with match damage. The second level is when he is able to make it so no one would attack you unless you are worth 70 points due to the time it would take and damage received, which is around 7 or 8 covers. 9+ covers is when he is actually useful for his moves and not just match damage, and it would be stupid for someone to attack a team with a Silver Surfer on it at that level. It isn’t unbeatable until around 11 covers though. So, it is really hard to say what point he is really useful in PvP.
You can watch my videos to see how he is at each cover level, and see how he works with his best possible current teammates before the next 5 star is released.
Part 1: https://youtu.be/_dpRmAeEd6o
Part 2: https://youtu.be/6hx_Hh4b47c
Part 3: https://youtu.be/bTxfPBYUPto