Upcoming Lissandra Changes
I really like the ideas coming forth:
'Iceborn'
Every 15s Lissandra's next basic attack deals 15-90 (+0.2 AP) bonus magic damage, doubled if the target's movement is impaired by Lissandra. Whenever Lissandra impairs an enemy's movement Iceborn's cooldown is reduced (3s for champions, 1.5s for minions).
Coming from a previous Lissandra main, I really like the fact that there is a window of time and usage of the passive where high-skill Liss's and Low skill Liss's are seperated. For example, I like that it can be used on minions, which forces her to think about how and when she uses the amped-auto. Please keep that. I'm also very happy the you continue to think about a buff/small tweak that includes her autos. I remember when you had started the dialogue and making her autos super intrinsic to her playstyle with the mega-buff transformation thing (I'm glad you scrapped that idea). But I like where this is going. I think the base cooldown to her passive should be quite high, to not imbalance her strength/damage too much. Possible 12 or more seconds. I think no greater than 20s, though. But it fits with Riot's development of "risk + reward" that forces you to step out of a champ's comfort zone and "safety." EDIT: I would change her passive so that minions don't reduce the cd of her passive. That would make it really hard to balance and would seem unfair. It just really doesn't seem to fit, and it's rewarding her for waveclearing? We already know that's a problem with our mages.... or.. was... Oh, and add 6 (or 9 if 3 interactions are required ->) seconds to my cd recommendation above because Lissandra should have to interact with the enemy (Q them) at least twice (maybe 3 times) before she gets to do that passive-auto attack thing.&END EDIT
Since you 'are' working on her right now, please consider making her ult targeting a lot better. Most Lissandra mains have a distinct key used to self-ult. A frustration of ours is when the enemy is too close to us, and we try to ult the enemy (and get the kill), but we end up self-ulting on accident and losing the kill. That is a large grief of mine when playing her and it feels really awkward and unsatisfying. Because we bound that special key for a reason, and I wish there was a way to disable self-ulting on the R key for just her (to prevent accidental self-ult). Does that make sense? Please consider that.
Also consider (if she needs buffs at some point) buffing her E range for defensive reasons. I personally think she will be strong with the new buffs/changes to her passive. And if she needs buffs after that, consider making her E range a tiny bit longer when running away from enemy champs (kind of like how 
and 
R and E, respectively, change depending on if the enemy is near or depending on their position).
I always wish Lissandra's Q range was longer, but I understand that would be OP on many levels. Just me dreaming tho ;)
and 
are easily the two most fun champions to play in the game. I've felt this way for a long time (been playing since season 3).
Take care
Love, Ace