[ultraman zoffy]

Ahhh... DCUC figures. It'd be easy enough to just cut the hinge joint off their feet and swap it out to make a rocker ankle if it weren't for their damn ginormous pins that Mattel uses! Inspired by a rocker ankle mod I saw on Fwoosh a while back where the original poster was trying to reuse the cut off DCUC ankle hinge by screwing a really tiny screw into it, I figured it'd be both easier (since tiny screws aren't exactly readily available) and cheaper to just use ball end sewing pins. Since the hinge joints aren't very thick at all, the pin is thin enough to stick into even the thinnest hinges Mattel uses while still being strong enough to prevent bending from regular handling/posing.
Basically, you just follow the normal boil/pop and cut steps that you normally would during a typical rocker ankle mod. While you could just push the pin into the hinge joint, I used my tiniest round-end engraver Dremel bit to create a hole for it, then cut the pin down to the necessary length. Pushing to hard on the pin could possibly bend it or cause the ball to fall off, so I'd recommend drilling. When you're done drilling, DO NOT install the pin into the hinge just yet.
Next, drill a hole into the foot just big enough for the ball of the pin to go into with a small amount of effort. You can then boil the foot, and push the ball of the pin just enough so that it's not all the way in but holds firm.
Apply some crazy glue to the metal end of the pin sticking out of the foot. Then, holding the foot, push the metal end of the pin into the hole you drilled in the hinge joint. Doing it this way will both sink the ball into the foot further while also pushing the pin deeper into the hinge.
See pics below for an idea of what you're doing and the end results. Bane can now stand flat-footed like a manly terrorist instead of resting on the inside edge of his foot like some kind of ballerina. lol Have fun! Let me know how it works out for you if you try it out.