I'm just going to put this whole thing to rest..
1: Dual raiders are designed around the concept that the longer it takes to kill them, the more deadly they'll become, until a point is reached where they will completely overpower you.
2: Debuffs of the dual raider were supposed to be the polar opposite of cleric buffs with a slightly higher base, making it so they can negate most of a clerics buff without needing as much charm, or else they would suffer too drastically from lack of ability to survive or deal damage.
What ACTUALLY needs to be done.
Definitely not a cooldown increase, that will not solve anything in this situation, as the problem is not about a relation to puri, it's about the relation of available buff amounts, gear bonus amounts and skill passive amounts.
The combined stat weights from gear + buffs is still inferior to a debuff from a CHA spec'd dual raider. The problem stems from the fact that
a] Clerics mspeed buffs have been reduced 1-2 times since the class re-balancing + skill updates.
b] Dual raiders status downs have NOT been touched since the re-balancing or skill updates [none of them, not the def, mspeed, or accu. The A-Speed was removed from the CHA affect during the balancing but not touched since]
So the fix is simple. Re-adjust the base level of mspeed down on the duals debuffs [status downs].
The level of importance is
1: Mspeed down
2: Accu down -this is also too high-
3: Increased application rates of wounded or apply to an additional single target skill.
There are also many other factors at play, however 1 thing is VERY clear, the status downs of a dual are not proportional to a clerics buffs, but~ they are closer in proportion to buffs provided from classes.
So, no, the cooldown doesn't need adjustment, purification doesn't need to be altered. The amount down needs to be lowered, or applied in "stages". Like stacks.
an example of this would be
1: Cast Enfeeblement / Crippling Storm
[@Skill Lvl5]: Applies ((100*SkillLvl)+Static Value)*Stack_counter = total
Max Stack 5
Stack duration 10 seconds
Cooldown Times: 5 seconds
Data Emulation
Lvl 1 @ 5 Stacks:: ((20*1)+15) 5 = 195 down [total]
Lvl 5 @ 5 Stacks:: ((100*5)+35) 5 = 675 down [total]
This provides the "over-time" debilitating effect they're designed to do, while also providing a more manageable status application + purification rate exchange.