My version of Cassiopeia

Deadly Cadence: When Cassiopeia kills a unit, she gains a stack of Deadly (max 3). Her next spell that hits a champion will consume one stack of Deadly and place it on the champion (once per spell, does not have a timer). Cassiopiea's poisons on Champions with Deadly will last an additional second for each Deadly stack on the champion. When an enemy champion reaches 3 stacks, the stacks will begin fading away, taking 5 seconds after which all 3 stacks are removed. During the 5 seconds, Venomous Strike will refresh on striking the unit.

Venomous Strike: Cassiopeia lunges a short distance, dealing damage to the first unit struck. If the unit is already poisonsed, Cassiopeia will dash to her original location, charming the unit. If the unit is not poisoned, Cassiopeia poisons it and she gains bonus movespeed.

Caustic Venom: Cassiopeia spits caustic venom at a direction. The ground becomes corrupted and deal damage to units in it as the AoE increases. Units that take damage from this poison will continue taking damage after leaving. Units hit by the initial blast are blinded for 1 second.

Aspect of the Serpent: Cassiopeia commands a snake to a target location. The snake will bite the first target it sees, prioritizing champions, and poison the unit. If the snake bites a poisoned target, this spell is refreshed.

Petrify: Cassiopeia's gaze for the next 10 seconds will place stacks on units that face her. Units facing Cassiopeia will gain a stack of Stone every .5 seconds and on the third stack, the unit(s) will be stunned and dealt damage. Cassiopeia's spells will deal true damage instead of magic damage to petrified units.