FORUM

Easier to explain with an example, But basically by switching gear and minor forging you can gain two set bonuses at once or make one set bonus persist with only 1 set item.

Example:
you have 2 items equipped.
One has Antique Toxin Rank 20
One has Ancient Shield Rank 20
If you equip an item fulfilling one set bonus
Toxin 20
Shield 20
Shield 20
you complete the set bonus and it Turns "On" the Shield Set bonus.
If you equipped a Toxin instead, or switched then only one instance of "shield" exists and it turns off, and Toxin turns on.
HOWEVER
If you switch from the shield 20 to an item with the default set Toxin 20 forged with Ancient shield 1/2/3... you keep both.
Since the forged ranks are placed in the Set bonus area when you switch from a fulfilled Shield 20 pair, to a shield 20 and a shield "X" it keeps the shield 20 (Since its the highest) active till you log out, and can be reapplied as stated.



I imagine the same could be achieved with a green item with rank 1, when matched with a set piece initially turned on, but I found it from a Toxin 20 set sword with +3 Toxin +3 Shield.
with a Toxin 20 set chest and shield 20 set helm.
I had switched from a shield sword to see how forged ranks of toxin effected the rank and saw that I had an active rank 20 shield from my helm, although my toxin set was boosted at rank 23.(Highest of each 23>20, 20>3).
Its not a graphical glitch, I entered maps and maintained the 14% shield with duel toxin, and after it properly updated after a log(or before a switch) it was properly 2.X%