I was thinking about the tier system used in this forum and something about how it should work came to me as an inspiration.
I thought about how a top tier character can beat any number of street levelers fairly easily -this depends on power sets but most of the time its true. Metalevel characters just cannot beat Trascendent characters -not counting prep here-, you can throw as many as you wish. In the same way is logic that any number of top tiers should be stopped cold by a Skyfather without outside help -the line is blurry between trascendent chracters and Skyfathers.
So one character from a higher tier should be able to destroy any number of characters two tiers bellow him barring spending all his/her energy or a conflicting powerset. I don't think its necessary for this to be truth for any character, but if you can destroy any number of characters of a certain character I think that you should be at least two tiers above them. Just as a general rule.
Yeah. I'm sure you could find plenty of cases where that doesn't happen on our tiers list. Trying to make it kosher with your proposed rule would literally be impossible....there would always be exceptions.
I aknowledge that there is too much variance to make a perfect rule, I supposed that if you are able to defeat any number of Silver Surfers/Supermen you should logically be above them, two tiers was an estimation -a rough one.
In any case, are there feats that by themselves imply possessing a certain tier?
You're asking what defines a tier, and there isn't a definition.
For the best estimation, just look at the tiers thread itself, because the best definition is the characters at that level.
Also, creating any rule along these lines would just make things more confusing because you'd get into lengthy discussion about exactly how many of a character another character could defeat, which are opinions that are as subjective as the list itself. Forming something that approaches consensus would be impossible