Collectible Card Game Headquarters

I used to play with Skiera's cube that's included in Forge, but I got tired of seeing both Tezzerets and other cards that didn't really have any synergy with the rest of the cube so I decided to make my own. This is my first attempt so it definitely could use some refinement. It's over 700 cards because I basically just threw all of my favorite cards together.

I plan on picking specific versions for each card, but I first wanted to get some feedback on the actual makeup of it.

Things I'm already considering changing:
- amount of mana fixing and dual lands
- each color's share of the cube and just size in general