My (warning: long) thoughts on where the Cass rework went right and wrong

I know the Cassiopeia rework has already been discussed at length, but I would like to chime in before the next set of changes make it to the PBE/Live. That being said, due to the sheer quantity of previous conversation and the number of points I wish to make, I will try to keep all my points brief and avoid hyperbole. Additionally, many statements I will make, such as those regarding cause/effect and purpose/intent, are opinions and may be wrong. If you disagree with anything I say, make it known.

The Good

Firstly, I think it is important to outline the successes and positive aspects of the rework, as any further changes should not diminish those.

1. Cassiopeia no longer has a lethal early game, followed by a snowballed mid game, ending in a hypercarry late game.
2. Her identity has been clarified. She is not a burn mage. Ticking away poison is not her goal. Singed, Brand, and Teemo already exist. She is supposed to twin fang enemies to death.
3. The first two points have been accomplished by removing her old passive, dialing back her poison damage, and making her twin fang ratios scale with level. All of which hinders her early game, but still allows for late game dominance.
4. Since she still needs to spam an ability, her twin fang now has a conditional mana refund/sustain aspect to replace the sustain lost from her old passive, this also opens her up to not necessarily building regen: now she can choose between pure mana and regen.
5. THE TWIN FANG RESET WAS FIXED AND THE ULT HITBOX WAS ADJUSTED HALLELUJAH!!!

The Bad

After all the above has been accomplished, Cassiopeia still needs a new passive. One that ideally would reinforce the the "constantly poison the enemy, and strike quickly when weak" play style, rewards people for playing that way, and would scale better as time went on. So the designers created aspect of the serpent. Common complaints about new Cass is that she is not as fun, has ZERO ability to trade in lane, and consequently cannot make it to her all-powerful late game. Playing her is like getting perfect CS with Nasus, but having to wait till your first inhib goes down to get the effects. I will argue that her new passive is in fact the ONLY thing wrong with her rework. My points are as follows, ordered from simplest to remedy, to most complex.

1. Veigar is now an anti-Cass. At every stage of the game, regardless of Cass performance, he will beat her. There is no reason why Veigar should be such a good counter to Cass in particular out of all mages.
2. Her damage scales exponentially with both her passive AND her twin fang level. Is this really necessary? It is awkward and complex. Especially relative to most other champions linear scaling.
3. All other passives in the game, by definition, reward you passively for playing the active parts of the champion properly. Because of the passive nature, every champion gets something out of it even if they are playing sub-optimally. Aspect of the serpent offers NO reward without optimal behavior. Simply put, passives ALWAYS give a champion something (save for my coming example), the level of the "something" they get is dependent on the level of proficiency the play has in using of the actives. This is not the case with Cass.
4. Most importantly, unlike ALL other champions (save for my coming example), new Cassiopeia effectively does NOT have a passive during her early game. While all other champions are reaping the small benefits of their unique attribute, Cassiopeia sits sad and weak in lane and will have an unreasonable time making it to a point where she is even remotely powerful.

The...Explanation

There are multiple avenues to address 1 and 2 if they are considered by themselves. I will not touch on those. 3 and 4 are my biggest concerns. I will use two example that are exceptions to 3 and 4, and I will use these exceptions to prove the rule.

League of Draven does not immediately benefit Draven like all other passives benefit their champions. In fact, he, like new Cass, has to stack by performing important actions (to Draven). The difference is in availability. While he is not getting Twisted Fates auto gold, he does have instant ACCESS to this gold. He has to kill someone. This may not be as easy, but Draven should be doing it anyway and it is always POSSIBLE. Cassiopeia on the other hand has no way to "trigger" her stacks. Once she hits 200 she is now in a 200 stack limbo where further optimal behavior does not reward her whatsoever, and realistically, she is perpetually in a large limbo of sorts due to her passive. This makes her passive more of a chore and far less responsive to proper play than Draven's.

Syndra's Transcedent, like Cassiopeia's passive, essentially gives her nothing until discrete points in the game. Unlike Cassiopeia however, Syndra has an EXTREMELY safe early game. She has damaging, long-range poke, good farming abilities, and most importantly: a powerful disengage. Once Syndra survives long enough she gains massive boosts to her damage, chase/kite, and team fight ability (generally in that order). Cassiopeia has no such guarantee of safety. Additionally, Syndra does not have to work at her passive. Playing good or bad, most Syndra's will get their first Transcendent bonus at around the same time, all she has to do is stay in lane, she doesn't even HAVE to farm. Cassiopeia does though (in fact her farming mechanic guarantees that the wave will push), and again, this means she has no guarantee of reaching her power spikes at appropriate points in the game.

The Proposal

Scrap her passive. I would say that even keeping only a slightly buffed version of her E's spell vamp on at ALL times would be more rewarding than her current passive. I think a possible route would have been to just nerf her old passive, like require 10 stacks to get to 50% mana cost reduction. In early levels it would just not be possible to spam q regularly enough to get enough reduction to go all in. Once she started brawling in team fights though, proper kite, ability use, and positioning would easily allow her to get her cost reduction.

Her new passive should still fulfill the design goals: reward players who keep up a constant, mildly annoying, supply of poison (without have the poison itself do everything). This passive should be available to her at all times, but like many passives, be weaker at first and scale with level and/or AP (think Lux). Players who are NOT as good at doing this should still have a way of benefiting from it, although far less so. Additionally I think the E's spell vamp should just be moved onto her E and scale along with it (it makes no sense for it not to).

I will now offer an example of a passive I think fulfills these design aspects. This is not "Rito listen to me and do as I say" this is just an example of the above concept with meaningless numbers:

Cursed Venom - Every time Cassiopeia damages an enemy champion (every second of poison, every twin fang, and every ult) they build stacks of Cursed Venom. Every time Cassiopeia casts twin fang on an enemy afflicted with Cursed Venom, twin fang does an additional amount of true damage equal to (CV stacks X 2% AP). Heals(and fountain?) remove the debuff in addition to other debuff removal methods (LIKE DEATH).

Clearly constantly poisoning an enemy benefits you here. I don't think that requires explanation. However lets examine either an inexperienced player or an opponent who is skillfully dodging. Even though you build up less stacks, if you decide to just go all in, you are still getting at least one Q or W worth of poison in, plus a few twin fangs empowering each other. Maybe you got of 3 twin fangs and your last twin fang hit with only 5 stacks at 100 ap. That means you got 22 extra true damage total. Even though you could've had upwards of 25 stacks and had more damage, 22 true damage in a fight is still better than nothing. Her current passive does not give you the same benefit/leeway. It is also extremely minimal, but still effective early game, and scales up over time. This new passive also fits thematically and makes her poison a powerful and noticeable element of her kit (just sayin).

TL;DR - Give her a passive that is fun and encouraging, not one that is punishing and laborious. Everything else (poison and E damage/cooldowns) can be fine-tuned around it. All other changes were great. Sorry for the great wall of text.