Idea for Lissandra Passive, etc.

So liss's passive is kinda meh, and I think a lot of people agree that giving her some sort of shield would be nice. So here's an idea for a passive:

ICEBORN

static cooldown: 120 seconds (?)

When Lissandra stops an enemy champion's movement (roots or stuns) she gains a spell shield for 1 sec (?). This shield can also block the bonus damage from autoattacks empowered by abilities (Talon's Q for example).

Question marks because I don't know if these are great numbers. This passive helps Lissandra enter a fight and not die immediately, but it also doesn't make her tanky. It also plays on Liss's anti assassin nature, which I think is a good thing to bring out in her. However, this passive does provide the issue of making an already mobile, poking champ harder to catch. Thats why in terms of numbers I went with a long CD and a relatively short spell shield. Glacial path takes about 1.5 seconds to go to max range, so this passive gives Liss a very good chance to escape. But, this shield only really works against assassins and fighters. It doesn't help her escape long ranged cc like a thresh hook as she needs to cc to activate her shield. However, it could allow her to recast her E if she's quick enough to ring of frost thresh before he flays her, etc.

Now having a passive like this would mean LIss needs a few other changes. For starters either Lissandra's mana regeneration is the worst of mana champions. Without a free to cast spell, her mana regen should up and her Q mana cast should lower. 85 per cast is high for a champ's bread and butter spell. Instead of having it be 85 at all costs, have it scale up to 85. Also, another change her Q should get is that it slows all enemies that it hits. I'm assuming it only ever slowed the first target because of her current passive having a shorter cd each time she cc'd an enemy.

Alright with these buffs to Liss, she in turn needs some nerfs. Her Q doesn't need to slow as much, if all enemies she hits are slowed. And though I have seen her played as a burst mage, I think Liss is more utilitarian. With a boost to her utility, it's only fair she would do less damage. I don't know if nerfing her Q's damage is best because Liss should be able to cast it a bunch, and feel like it's doing damage when it hits. Since it's primarily a utility skill, Glacial Path doesn't need to do as much damage as it currently does. That being said, I think a healthy nerf would be Liss's Frozen Tomb doing a bit less. In both of these nerfs, I think nerfing the scalings over the base damages would be best. This does make it harder to play Liss as an "ice" cannon, but with the buffs to her Q, she should still be able to do enough damage when building straight AP. It does encourage the player to build Liss as more of a utility mage.

I think focusing Liss as being the utility mage who is the first to jump into a fight is the right kind of identity for her.