Riot won't revert cass passive, so how about this:

Since Miasma is almost worthless at lower levels why not turn it into a safer way for Cass to farms stacks. Here is how I suggest doing this:

1. Increase the cool down slightly at higher levels.
2. Lower Miasma's cost significantly at lower levels, have it be the same at level 5.
3. Make miasma do the same damage but over 6 seconds at level 1, and over 2 seconds like the live version at lvl 5.
4. Add to Aspect of the Serpent's 200 stack: Twin Fang increases max level Miasma's duration by .5 seconds. Add to the 400 stack: Twin Fang increases max level Miasma's duration by 1 second.

What this would do is turn Miasma into a cheap safe farming tool at lower levels. Every time you land Miasma you would receive 6-13 stacks instead of the current 2-9 stacks. The altered cost would allow players to use Miasma as a way to farm up stacks, safely and reliably. The change to the passive gives players a reason to put points in Miasma once they are done farming stacks in lane.

**Old Miasma ** RANGE: 850 COST: 40 / 50 / 60 / 70 / 80 mana COOLDOWN: 14 / 13 / 12 / 11 / 10

Cassiopeia throws a growing cloud of poison to a target location, granting sight of the area and growing from a radius of 125 to 250 over 7 seconds. Enemies in the area are poisoned, slowed (25 / 30 / 35 / 40 / 45), and take (0 / 15 / 20 / 25 / 30 (+ 10% AP) magic damage **per second **for 2 seconds. Continual exposure renews the poison.

**New Miasma ** RANGE: 850 COST: 22/ 45/ 57/ 70/ 80 mana COOLDOWN: 15/ 14/ 13/ 12/ 11

Cassiopeia throws a growing cloud of poison to a target location, granting sight of the area and growing from a radius of 125 to 250 over 7 seconds. Enemies in the area are poisoned, slowed for (10 / 20/ 30/ 40 / 50) 2 seconds, and take (20 / 30/ 40/ 50/ 60(+ 20% AP) magic damage **OVER ** 6/5/4/3/2 seconds. Continual exposure renews the poison.