Automatically swap your attack modifier base on your attack cooldown.
Here is the explaination, example :
1- You got 2 attack modifier, Elder Parasite and Shieldbreaker.
2- Your hero attack cooldown is for example, 1.5 seconds.
3- The 1st attack will give you lifesteal from Elder Parasite.
4- After 1.5 seconds (which is your hero attack cooldown) and you attack again,
it will apply Shieldbreaker effect to the attacked enemy.
5- Then after 1.5 seconds again, your attack turn back to lifesteal. Then, Shieldbreaker back again.
6- So, let say your hero now is level 25 and it's attack cooldown for now was already 0.6 seconds.
7- Then, the time between the Elder Parasite and Shieldbreaker to swap will be 0.6 seconds.
