Aatrox in URF
Probably going to fall on deaf ears since I rarely ever see Aatrox at all URF or otherwise, but the heal embargo basically kills off his sustain potential, and by extension, Aatrox himself. Aatrox depends on that huge burst heal below half-health on his W to offset his significant health costs early on in the game. With the heal embargo in place, Aatrox cannot sustain himself at all; and doing practically anything gets him killed.
Spamming abilities, one of the key features of URF, is something that is not easily available to Aatrox because his resource costs (health) are still very real in this gamemode. His incredible sustain that normally counters this is neutered by the heal embargo, leaving him in a completely useless and sorry state. On the bright side, that passive cooldown buff is really noticeable.
First champion I've seen that has actually been nerfed through URF. Just aallow Aatrox to be aan exception to the heal embargo.