Out of the loop (hardly played since the 25 cap) but to me, the light damage needs to scale up with epic levels somehow.
How about this:
Pal7: You get +1d6 damage (double with two-handers). If your overall character level is 23 or higher, this damage is tripled. If you are level 27 or higher, it is instead quadrupled.
Pal13: Improves to 2d6. Scales as above at character level 23/27 to 6d6/8d6 with one handers, 12d6/16d6 with two-handers.