As i understand it, "Blast" is the stupid mans cone area spell. Which is why I would prefer a cone instead of a gimped circle. I would still want to keep it  relatively easy, and it seems cones for short ranges are pretty easy. At long distance it can get out to 20 squares as like 29th level. That is seriously better done with a string.

I read someone mention it on the wizards forum a few days ago. The clues were, it originates from a space adjacent to you out a distance, and people are dumb.

I'm sure this has something to do with the casters chi, or contras, those special spiritual parts of everyone's body that maintain the balance of ones life force. So it makes perfect sense that the distance of his area effect spells are directly correlated with the position of his body *life force.* And his powers, as we all can sense from the mother life force, travel farther when carried on the diagonals of the holy square grid that mandates all forces, rather than accounting for actual physical distance from origin.