There are a few things in game which cannot be enhanced at current. one of these is Power Duration everything from Build Up to Click-type effects, number of ticks of damage in DoT, duration of castings/summonings such as Quicksand or other field type powers or "Blaster: Electrical Blast: Voltaic Sentinel".
For the name, the question is theme; we could give the name a temporal theme, or we could theme the name by something to do with willpower, training or extra effort.
I was thinking this should be a Global set "Global Duration Enhancement" UNIQUE
The Proc could be several things:
1: The first thing that comes to mind is perhaps a Global 33.3% duration increase to all applicable powers with positive effects to self, other, or negative effects to enemy, pvp enemy player.
2: The second thing which comes to mind is a +100% duration to the slotted power.
Another issue is the set construction, it'll be applied to many different types of powers; +HP, +Res, +Defense, +Speed, +Damage, +Accuracy, +Recovery, +Regen, +ToHit, +End, -Rech, Endurance Discount/End Mod, End redux, Timed Summon Duration, +range, and debuffs of all these so enhancing any of those effects will have to be under Damage, Accuracy, End Redux or Buff/Debuff(everything else including self-buff and buff other and debuff)
1: Proc
2: Duration
3: Duration/End
4: Duration/Damage
5: Duration/(Buff/Debuff/Effect)
6: Duration/Accuracy
This set needs work, as at the moment it's great for duration increase, likely increasing durations well over 150% which for a 10 or 20 second duration would be 25 to 50 seconds, but it doesn't really add much else. maybe +/- 34% or 40% enhancement to everything else in the slotted power.
perhaps this can be fixed with bonuses? not really sure what to give it. maybe something special for all 6 slotted like a +10% Global Durable Effect Enhancement (+10%% to effects of all powers with durations)
this really needs discussion, it's just an idea I had that wasn't discussed yet to my knowledge.