[Lucid:]

I don't like his passive from a design standpoint.
Zac, Anivia, and Zilean all have revive abilities, and on their own they are fine as long as they have counterplay. Counterplay is something that the champ designers have been talking about for a really long time in balance discussions, so I am VERY surprised that this guy slipped through in this state.

Zac's passive has a 300 second CD, and after you kill him, you have 8 seconds to kill all his bloblets. They can be killed by any kind of attack including smite, and it is plenty of time to kill him if you decide to focus him. If you don't want to focus Zac's bloblets, that is a decision and he will respawn after 8 seconds with 50% health or less.

Anivia's egg has a 240 second CD, and the egg actually has NEGATIVE armor/mr until level 12 at 5 armor/mr, then level 15 at merely 20 armor/mr. Those are all less defenses than even the squishiest champion base values, not to mention typical runes/masteries/items. Anivia will come back from her egg 6 seconds after death, but again, whether or not to focus Anivia egg is a CHOICE.

Zilean's Ultimate is, well, an Ultimate. Although the CD is reduced by CDR and his W, it still costs a nice chunk of mana, and it takes up his ultimate slot. Only one of Zilean's spells actually does damage, so it's fair to have a 180 second CD on the revive. The amount of health revived is also fairly low unless Zilean builds AP, in which case it scales with 2x his AP as extra health restored. Zilean's ult revive has a 2 second stasis period, same as GA.

Speaking of GA, it costs 2600g. The stats it gives do not make the item efficient on its own; the armor/mr on the item are only worth around 1500, which makes the revive passive (30% of your health restored) cost 1100g. GA also has a 5 minute CD.

Now let's compare all these abilities to Aatrox. Blood Well has a CD of 225 seconds, which is shorter than either Zac or Anivia. This reduces the opportunity time to make plays on Aatrox while his passive is down. Aatrox is completely invincible while reviving, which means that you have NO CHOICE whether you want to focus his corpse down or not. There is no way to stop his revive, prolong his revive, or reduce the amount of health he revives with. The only counterplay available at all is to burst him down before he uses spells to build up his blood well. This is very poor because you can't stop him if he engages with a blood well already charged up, such as coming from the jungle. His blood well revival scales twice with his level. On top of this, Aatrox gains offensive stats (attack speed) from his blood well, making it both a defensive and offensive ability with no counterplay.

I heard a suggestion today to change his passive from complete invulnerability to something more like Yi's meditate, where he regens and gains a ton of armor/mr, but he can be targeted, ignited, interrupted by CC, you know all those things that let you make decisions on how to deal with him. I would love to see it taken in that direction because honestly I just think the passive does too much, with too strong of numbers.

The rest of his kit doesn't really bother me (except maybe having a knockup. A slow would be fine, but hard CC on a melee carry with a gapcloser is a bit much). Hard CC screws him up and ranged kiters can usually keep him at bay.