What happens if you have Superior Will and succeed on a Saving Throw (in the start of your turn) against the Dazed condition from Certain Justice (the 11th power from the Champion of Order paragon path)? Do you get rid of the Dazed condition forever? Do you still have to succeed on a Saving Throw if the target is marking you? How does it proceed?
The dazed effect ends.
Certain Justice specifies that "If the target is marked by you, it is also weakened and dazed until it is not marked by you."
Superior Will specifies that "If you are dazed or stunned, you can make a saving throw at the start of your turn to end that effect, even if the effect doesn’t normally end on a save."
The daze is an effect caused by Certain Justice's conditional. As you are dazed while under that effect, you can make a saving throw at the start of your turn granted by Superior Will. If the saving throw is successful, the effect ends.
Therefore, saving on the save granted by Superior Will removes the dazed effect from Certain Justice's conditional, rendering it into, effectively, "if the target is marked by you, it is also weakened until it is not marked by you."
Does this remove the dazed condition forever? In so far as the daze imposed by Certain Justice, yes. If you are dazed again from another condition, or if your foe regains Certain Justice and re-applies it to you, you will be dazed again.
Do you still have to succeed on a Saving Throw if the target is marking you? This question doesn't really make sense, as you have to be marked in order to be dazed. You can't make a saving throw against dazed if you are not marked, because you are not dazed if you are not marked.