I think I got better way to balance 'Cast on X'.

I was thinking a lot since i saw today's patch and that got me thinking about better way to balance it making it fun for casual players because as it is someone who got no knowledge of this game will see this aura equip it see that it cast only every 10-20 monster and sometimes it triggered spell completely miss or cast on monster that is already dead and they will probably think that it's useless and won't even give it a chance.

So my solution would be every cast give 1 stack that increase energy required by 100 energy (for linear scaling) or just times 1.5 (for exponential scaling)

linear scaling calculation
100+100x(amount of stacks)
so with 10 stack it would be 100+100x10=1100 energy for next cast

exponential scaling calculation
100x1,5^(amount of stacks)
so with 10 stack it would be 100x1,5^10=5766 energy for next cast

Every stack would have apart 3 seconds timer so it wouldn't stack infinitely and you wouldn't have to stop casting and wait 3 seconds. Energy would still save so if you had 900/1100 (with 10 linear stack) energy and lost 2 stack it would be 900/900 and you would trigger spell

I think it would solve most problem with too fast triggering because eventually you would reach place when you can trigger it only 1 time per 3 seconds and still give more casual players chance to trigger it on every first frozen monster.
I personally think exponential scaling would be better.

If you agree of have other idee or maybe some change of addition that would make it better i would be happy to discuss it and I would love if this post would reach GGG so maybe they will consider it. So if you agree and want to support this idee please at least reply to this post.