Well first off many many many people dont understand % proc.
(Those of us from shaiya knows all to well %)
(Using illusion 5 / 10% as all examples)
The percentage is based on each attack not the fight as a whole
So saying it did proc 10% of the time in the fight is WRONG thinking.
For the incorrect thinking, the AI would have to look at the combatants and calculate ahead of time
* how many attacks will be aimed at you, which means the RANDOM attack is bogus
Now the AI cant count for if/when mages u heal skills which would extent the fight
Players using heal runes or def runes to extand the fight
Use of fighter shield or dodge regen usage
Archer hp syphon usage
And as such cant make a base number of attack to get the 10% u expecting.
So that means the correct way to look at it is proc is calculated vs each attack and as such its 10% chance per hit.
Thus if u get attacked 110 times in a full fight
u could fairly well not proc once which just means u very unlucky (kinda failing enchant multiple times at 90% success).
or u could fairly well proc everytime just means u got super luck and need to play the lottery.
But expecting it to proc 11 times out of the 110 is incorrect thinking.
Basically illusion is working how its supposed to
Remember before it was glitched/bugged and proc alot more then it supposed to.
So now that the devs fixed it, we get QQin in forum on they fixed the bug i enjoyed using to my advantage.