Some ideas for a new Lissandra passive

DISCLAIMER: Most, if not all, of these passive ideas, would require nerfs to other parts of Lissandra's kit, as most of them are an improvement to her current passive.

1: Heart of Ice: Static CD: 20/17/14

Passively, when Lissandra damages a movement-impaired champion, she gains a 40 - 90 + (0.30 AP) health shield. The shield stays until broken, with secondary procs refreshing the shield, not stacking it.

2: Frozen Touch:

Passively, Lissandra's basic attacks deal 5 + (2 per lvl) + (0.15 AP) bonus magic damage, to movement impaired units.

3: Hand of the Watchers:

Passively, after using an ability, Lissandra next attack drains 1 - 3% + (1% per 100 AP) of an enemy's mana and fills her mana bar by the same amount. If the enemy doesn't use mana, Lissandra instead drains 2 - 6% + (2% per 100 AP) of their health and fills her mana for half of the amount drained.

4: Empress of Ice:

Passively, killing minions and small monsters grants Lissandra 1/1/2 stacks of True Ice, while killing champions, large, and epic monsters grants 5/5/10 stacks of True Ice. When above 25 stacks of True Ice, Lissandra's abilities deal bonus true damage equal to 3/4/5% of her maximum mana. When above 50 stacks of True Ice, Lissandra becomes immune to slows. When above 75 stacks of True Ice, Lissandra's abilities cost 15/20/25% less mana. When above 100 stacks of True Ice, Lissandra's slows are 15/20/25% stronger. True Ice stacks are capped at 100, with 100/75/50% of stacks lost upon death.

5: Iceborn

Casting abilities grant Lissandra stacks of Iceborn. At 5 stacks, Lissandra next basic ability will deal 20 + (3 per lvl) + (0.15 AP) + (0.03 Maximum Mana) bonus magic damage and will restore 10/12/14% of Lissandra's missing mana.

Thoughts?