10 Ranks: If you exceed the DC to demoralize a target by at least 10, it is panicked for 1 round or frightened for 1d4 rounds (your choice) and shaken thereafter.
And the target gets a will save.
Using demoralize on the same creature [that you already demoralized] only extends the duration; it does not create a stronger fear condition.
Say I use skill unlock for intimidate twice on my turn. Each time, opponent fails save and is panicked for 1 round and shaken for 3. So would the final effect be:
A. 2 rounds panicked, then 6 rounds shaken
B. 1 panicked, then 3 shaken, then 1 panicked, then 3 shaken
C. Unclear, go with A since it makes more sense.
D. I'm missing something and its none of the above
So, normally when you use Intimidate it does not stack with itself to create stronger fear conditions.
With the skill unlock, special things happen if you exceed the target DC by an amount.
In this case, if you exceed the target DC by 10 (normal DC is 10 + the target's Hit Dice + the target's Wisdom modifier) then the skill unlocks says that "it is panicked for 1 round or frightened for 1d4 rounds (your choice) and shaken thereafter.* A Will save (DC = 10 + your number of ranks in Intimidate) negates the frightened or panicked condition, but the target is still shaken, even if it has the stalwart ability."
So it is panicked for 1 round or frightened for 1d4 rounds. And then would be shaken for a number of round equal to 1 round per every 5 you beat the normal DC by minus the number of rounds panicked or frightened.
Then on the next round you attempt the same thing again. This time, the DC increases even more because "You can attempt to Intimidate an opponent again, but each additional check increases the DC by +5. This increase resets after 1 hour has passed." Eventually, someone can no longer be shaken by you.
You determine the results the same way as above, and I believe the correct way to run it is to add the duration together for each level of fear condition (since normal use of intimidate extends the condition), and have them affect the target from most intense to least intense.
Normally, the effect from the skill unlocks cannot last longer than demoralize normally lasts (1 round +1 additional round for every 5 by which you beat the dc). I assume that with the enforcer feat, the fear from skill unlock would last longer? So at levels 15 or 20, "panicked thereafter" or "frightened thereafter" would end up lasting as long as the rounds of shaken from enforcer? My assumption is yes, but I could see someone interpreting the skill unlock duration to be a hard limit, as opposed to reading "skill unlock lasts as long as you are able to demoralize the opponent."