Removing the following from the Mega Man example:

• Sort-of example: In Mega Man 2, the cycle of boss weaknesses only had 7 links... because Metal Man was weak against his own power. This doesn't help in the initial fight, obviously, but in the rematch he only takes two hits if you know this.

For two reasons - one, the boss in question is fairly easy to take down using the basic weapon without taking too much time, so he's clearly not this trope. Second, there is a two-tiered vulnerability circle in Mega Man 2; most players don't bother learning it in part because of the secondary weaknesses for most bosses and in part because the Metal Blade is a Game Breaker (for the record, the actual weakness for the boss in question is the Quick Boomerang).