After making powers for all the easy to find dice, I picked up a set of 24 sided dice, and set out to make a new power for them to use in my dice army fighting game, Armies of the Dead. I went through at least 5 powers before I settled on the final one. One thing about expanding games and bringing in new pieces that can be difficult (at least for me, since I have strict design standards) is finding a way for them to be unique, do things differently than other pieces, and not just be more color in the game. By color I mean decorative variety without strategy variety. The simpler your game is, the harder it is to find new concepts and pieces. Sometimes you have to enlarge the game's statistical structure. That's just a design tidbit for you.
Here's the new unit:
D24: Souldrinker: when it sends a piece to the graveyard, it may take a piece from your graveyard to your reserves that has the same number of sides or less than the piece it sent to the graveyard. Doubles: Take any piece from your never-never land into your reserves.
See the whole page of errata, conventions and new unit here.