Inb4 people complain about "well how do I get 15 Magic Pen now?!!!"
WE TROLL TOGETHER DOUBLE 
bump to give the ABILITY to wear boots again
SNAKES DON’T NEED BOOTS Cassiopeia gains 4 movement speed per level. Cassiopeia cannot purchase Boots items.
True to her half-snake nature, Cassiopeia bears twin identities of “poison mage” and “lightning-fast viper strikes.” However, the high-input gameplay of Twin Fang has left Cassiopeia wanting for greater impact in her poisons, instead viewing them as a gating condition for her combo damage.
Rather than giving her more damaging poisons (Singed has that market cornered), we’ve sharpened Cassiopeia’s poison fantasy by linking Miasma to another snake fantasy: immobilization. The new Miasma lets Cassiopeia weaponize her own immobility by bringing opponents to her level. By limiting the ability of champions to leave her kill zone, Cassiopeia dictates the ranges of an engagement, keeping foes at a distance where she can wail on them safely. Should her opponents play around Miasma, however, Cassiopeia loses that control and faces swift punishment from the champions she sought to keep at bay. General
BASE MOVEMENT SPEED 335 ⇒ 328 SMALL SCALE ADJUSTMENTS Several of Cassiopeia’s other base stats have been slightly adjusted ICONS Cassiopeia has all-new ability icons UPDATEDPassive - Serpentine Grace SNAKES DON’T NEED BOOTS Cassiopeia gains 4 movement speed per level. Cassiopeia cannot purchase Boots items. Q - Noxious Blast COST 40/50/60/70/80 mana ⇒ 60/65/70/75/80 mana COOLDOWN 4 seconds ⇒ 3.5 seconds DAMAGE 75/115/155/195/235 ⇒ 75/120/165/210/255 RATIO 0.45 ability power ⇒ 0.7 ability power CAST RANGE 850 ⇒ 750 BONUS MOVEMENT SPEED ON HIT 20% ⇒ 30/35/40/45/50%, decaying over the duration UPDATEDW - Miasma Cassiopeia spews venom in an arc in front of her, leaving toxic clouds for a few seconds. Enemies in the cloud are continually poisoned, slowing and Grounding them, prohibiting the use of movement abilities.
COST 70 mana COOLDOWN 22/20/18/16/14 seconds DURATION 5 seconds DAMAGE 20/35/50/65/80 per second RATIO 0.15 ability power per second SLOW 40/50/60/70/80%, decaying over the duration RANGE 550-800 CLOUD RADIUS 160
E - Twin Fang COST 50/60/70/80/90 mana ⇒ 60/65/70/75/80 mana COOLDOWN 5 seconds ⇒ 0.9 seconds DAMAGE 55/80/105/130/155 ⇒ 52-120 (at levels 1-18) RATIO 0.55 ability power ⇒ 0.1 ability power REMOVEDCOOLDOWN RESET No longer reduces the cooldown to 0.5 seconds upon hitting a poisoned target REMOVEDMANA POSITIVE No longer refunds an additional 1.5% of Cassiopeia’s maximum mana on kill (still refunds 100% of the cost) NEWSNAKE BITE If the target is Poisoned, Twin Fang deals an additional 10/40/70/100/130 (+0.35 ability power) damage NEWHEAL If the target is Poisoned, Twin Fang also heals Cassiopeia for 5/10/15/20/25 HEAL RATIO 0.1 ability power
R - Petrifying Gaze COOLDOWN 120/110/100 seconds ⇒ 120/100/80 seconds SLOW 60% on targets facing away ⇒ 40% on targets facing away
If you can't buy boots, you now have a slot spare for either 
or 
