As I said with my post regarding the Ranger and his Master Hunter apex ability, I've been looking at the nuts and bolts of the base classes and found that the DC of the Rogue's apex ability, Master Strike, doesn't scale up when she becomes epic, unlike the apex abilities of several other classes. Therefore, may I suggest one minor change to the Master Strike ability description, that would keep the status quo at level 20, but then would scale up as appropriate:
"Regardless of the effect chosen, the target receives a Fortitude
save to resist with a DC equal to 10 + 1/2 the rogue's level + the rogue’s Intelligence modifier."
