About Cassiopeia and the recent PBE changes
Since Stashu's thread has disappeared entirely from the radar, I'll have to bring up my concerns in a different manner. I'd like to address the recent Cass changes on the PBE in this thread in hopes of raising awareness about what's really going on.
EDIT: It turns out they had the audacity to raise the stackcap on her passive from 400 to 500 (!) without even telling us. This is an outrage.
Stashu, I've seen your changes on the PBE and I must say I'm very disappointed. I expected far more from you after all those weeks of waiting, meanwhile Cassiopeia will remain in a very questionable state until season end (still no changes in 4.19). That's almost 3 months of playtime denied by your rework alone so far.
I'll explain to you exactly why your poison-changes are inefficient at raising her viability. My primary issue are her gutted ratios (0.8 -> 0.45) since you didn't fix them with this change. By slapping a multiplicator on them (25% up to 50%) you hardly make them any better, they're still vastly inferior. And why do you insist on nerfing her flat damage? Let me give you a mathetical example of what to expect ingame:
starting conditions (in this specific order) 40 AP (0.45) / Q rank 1 - 65 damage; 50% total damage increase (max bonus applied)
18 dmg (from 40 AP) + 65 dmg = 83 dmg + 50% (41.5 dmg) = 124,5 poison damage Q (45, rank 1) + E (30, rank 1) x2 = 105 mana spent
best possible conditions (in this specific order) 200 AP (0.45) [most likely amount once Q fully leveled] / Q rank 5 - 225 damage; 50% total damage increase (max bonus applied)
90 dmg (from 200 AP) + 225 dmg = 315 dmg + 50% (157,5 dmg) = 472,5 poison damage Q (65, rank 5) + E (35, rank 2 [lowest possible if Q leveled]) x2 = 135 mana spent
That's a lot of mana spent on merely poking someone, and that's already an unrealistic scenario considering that you'll never get the full damage after applying your Q since one poison-tick will already be wasted once your E arrives. With the second E, you'll only get the full 50% bonus on the third poison-tick.
These numbers cannot be achieved, no matter how good you are. The reward appears horrendously low compared to what you'd get with pre-rework Cass (and that without even getting into E-range):
starting conditions (in this specific order) 40 AP (0.8) / Q rank 1 - 75 damage
32 dmg (from 40 AP) + 75 dmg = 83 dmg = 107 poison damage Q (35, rank 1) = 35 (!) mana spent
best possible conditions (in this specific order) 200 AP (0.8) [most likely amount once Q fully leveled] / Q rank 5 - 235 damage
160 dmg (from 200 AP) + 235 dmg = 395 poison damage Q (75, rank 5) = 75 (!) mana spent
Now those are some great solid numbers and they only require you to cast a single ability while keeping your distance, and it's a lot cheaper aswell. Just landing another Q would make your changes pale in comparison, and it'd get EVEN cheaper thanks to her old passive.
Oh, and it doesn't require you to mark every single poisoned victim with your E which would only make you waste even more mana and time. Let's face it, it'll take a lot more to make her as good as before, you're just not trying hard enough.
You need to stop taking something away from her to justify any "improvements" - if a champion is underpowered, you should keep adding until they're up to par and NOT remove something they already had before. I fear her laning phase will be even worse after those changes since you took away her sustain in exchange for such an inefficient bonus to her poison-damage.