I’ve seen a couple bug threads where the tooltips are confusing people, so here’s some points of clarification;
Raging bull doesn’t work?
Raging Bull does work, but the tooltip is misleading. Instead of building and spending stacks on every attack, you do not gain stacks on an attack that is spending them. Basically, you only get the damage bonus on every other swing.
To test: If you hit a single target multiple times in a row (I suggest Flak Armored), you should notice the damage go between 2 values. The lower one is the stack build, and the higher one is the stack spend.
Note: Raging Bull only appears to boost damage on the first target hit, and not cleaved enemies.
Knife Through Butter doesn’t work?
Knife Through Butter does work, however, most don’t realize what the requirements actually mean, and what the Feat does.
The description of “Fully Charged Heavy Attack” means you must hold the button until the attack goes off by itself, which nobody does because it’s a lot of extra time for something that doesn’t give you extra damage. If you do this with KTB, your heavy swings will cleave through all enemies, including armored ones.
You can test this by putting on KTB then doing heavy cleave swings at the Armored Carapace enemy with something like the Shovel. If you release the cleave attack manually, it’ll stop when it hits the enemy, however if you hold it all the way through, it will do the complete swing.
Note: Heavy swings with the Shield + Club already cleave through armored units, and since the other heavy weapon attacks cleave through everything but 2-3 specific types of enemies, this Feat isn’t worth taking.
IMO, Payback Time is the only worthwhile level 25 Feat until the other two are addressed to be more useful.