User blog comment:Porchmunkyforlife/Karach/@comment-24420226-20140409211948/@comment-24420226-20140411011659

The idea of a stacking resource intrigues me. This also makes it hard to judge his power. The exact impact of the shields depend on the precise values he would be getting. Perma-shielding is something that you need to be aware of, but again, whether it's actually OP depends mostly on how strong the shields are.

With the way regenerating and expending Darkness on him works, it's a little tricky to get clear idea of the numbers. To properly balance him as is, you would have to play-test the heck out of it and find the right values for his Darkness stacks. But I have some simple(ish) number crunching.

Assuming that he has ideal farm for a laner at ten minutes (100 cs and getting all 17 cannon minions) with no kills, and has 1 rank in his ultimate with 100 AP (just to simplify calculations):

He would have 1170 maximum darkness with the above score. Upon the inital cast of his Ult with full Darkness, he would gain a 292 shield. If he hits no targets for the duration of the toggle, his shield will increase by 43 at the next stage of Darkness expendeture, then 41, then 39, and so on, gradually decreasing as he loses Darkness. If over the duration of the Ult he hits only 1 enemy champion with enough MR to reduce the damage by 25% (~30 MR) and uses no other abilities or attacks, his first shield will still be 292 but he will get Darkness refunded to him. This causes the next expenditure from his ult to refill the shield by 45, then 43, then 41. If he hits two champions (with the same MR) over the duration, he will be refunded more Darkness. Again, the initial shield will still be 292 but the next sequence of shields will start at 46. With three Champions, the sequence of shields start at 48. Regardless of how many targets he hits, everytime he hits the magic 25% Darkness amount the burst won't grant him a bigger shield, but it will refund more Darkness, extending the ult duration and the number of times his shield gets refreshed. Even if he starts using other abilities to further refund Darkness, with 1170 maximum darkness the size of the smaller shields' value will never exceed 58 since he can only expend Darkness in 5% increments (assuming he doesnt score kills during the Ult).

292 is comparable to the amount of health Lulu can grant with a rank 1 Wild Growth, or her shield from Help Pix if she decides to max that first. Given the above numbers, I'm not too worried about either that or the subsequent smaller shields being naturally OP. The problem is he if starts getting too many kills, the shields might start getting way out of hand for the enemy team to effectively deal with, making him actually unkillable. I might suggest implenting a cap for the shield amount that scales as he levels. But again, with out running a more thorough test of all the scenarios, it's hard to gauge the exact strength.

I hope that wasn't too much to chew :P