An idea on an ability

I was thinking about fizz's w, seastone trident, and a thought occurred to me. What if the DOT stacked. (DOT = damage over time) So I thought of an idea for a potential ability of any new upcoming unknown champions. The ability would empower your auto attacks for 5 seconds.

For now lets call the DOT, poison. Tagging any enemy unit with the empowered attack would place a stack of poison on the unit. The poison lasts 5 seconds and additional auto attacks on the target increase the stacks of poison but DOES NOT refresh the duration of the poison.

This would introduce a slightly new mechanic to the game. Like most auto attack steroids, there is a short time frame for utilizing it but in this case, the ability ramps up at an alarming pace but the effectiveness of the ability is diminished over the duration.

Example stats for the ability would be:

10/15/20/25/30 damage/second for 5 seconds for each stack of poison. This would total out at 50/75/100/125/150 damage over 5 seconds for 1 stack.

But say you have 1.0 attack speed and deal two consecutive auto attacks and the ability is at level 5, you would deal 30 damage over the the duration of the first and second auto attack, then 60 damage each second for the remaining 4 seconds, dealing 270 total damage over 5 seconds.

The intervals here represent the damage dealt for each second over the 5 second duration. At 3 consecutive auto attacks, it would deal 30/60/90/90/90 (total- 360) damage. At 4 consecutive auto attacks, it would deal 30/60/90/120/120 (total- 420) damage. At 5 consecutive auto attacks, it would deal 30/60/90/120/150 (total- 450) damage.

Maybe add in a 10% ap ratio damage per second for each stack, totaling 50% over the duration. So according to the above conditions: (.1/.2/.2/.2/.2 AP) (.9 AP total) for 2 consecutive auto attacks. (.1/.2/.3/.3/.3 AP) (1.2 AP total) for 3 consecutive auto attacks. (.1/.2/.3/.4/.4 AP) (1.4 AP total) for 4 consecutive auto attacks. (.1/.2/.3/.4/.5 AP) (1.5 AP total) for 5 consecutive auto attacks.

Pretty much what this says about the ability is that the ability has very large diminishing effects near the end of the spell but is very rewarding if you can put as many stacks as possible at the start of the spell.

What do you guys think?