Technically, a Knight of the Cross is merely (and I use that term with all due trepidation and caution) a Champion of God with a Sword of the Cross.  I can't think of a reason why, should the campaign limit on refresh rise over time to permit such a development, one might not advance from a baseline CoG to a KotC.  But that's a matter of plot, not mechanics: if we build part of the campaign around someone's rise to power, then it should be cool<br/><br/>I have a bigger problem with the whole 'only three at a time' thing, which is similiar to my raised eyebrow at 'only one' Knight for the Seelie and Unseelie.<br/><br/>But then, by their very nature, games of this sort are not canon.  So there might be more than one way to achieve that pinnacle.