Just a note, it's designed to be used in a D&D 3.5e or perhaps even Pathfinder system. I will be detailing two different types of Mana use (one for general use, another for a Clash of the Titans duel between Planeswalkers) and as such it's mainly meant to function alongside other classes and not be as powerful as they're regarded as being.
The above is more like design notes than a finished product, posted for some feedback and suggestions while I work on the end product. I think more class features may need to be added (or not; they already have more than a generic wizard, access to more spells, more spells per day and more bonus feats). There definitely need to be more Planeswalker related feats but I'm not sure what yet... maybe one to reduce the cost of a favored Mana type at mid-to-high levels?