Lissandra Passive and W suggestions
First of all I want to start by saying I'm no Lissandra expert, just somebody that really likes her but can't connect with her playstyle. I find it a bit weird for such a slow, squishy mage to have to sit on an enemies face to do damage. It's strange to me. I don't usually like to voice my opinions or make suggestions about champs who aren't Karma, as I don't wish to cause offence to other mains, but eh... what's the worst that can happen, downvotes? :/
Passive:
For her passive I was thinking something simple like increasing her damage to immobilized targets. I feel as if her damage isn't really as good as other mages, all of which have more range and are much safer than she is.
Ring of Frost:
I was thinking about what could make her feel a little more... comfortable, maybe? Then I remembered Darius' Q update with the delay and outer ring bonuses... see where I'm going with this?
What if Lissandra's "Ring of Frost" was an actual ring of frost? Increase the spell radius from 450 to 550, add a brief (1 second perhaps?) delay/telegraph and make the root apply from between 400 to 550 units. Enemies within the 400 unit inner radius are slowed instead of rooted.
Disclaimer: numbers mentioned above are purely for illustrative purposes, I'm no dev.
Now, I'm not sure how power budgets work exactly, but I was thinking adding a brief delay/telegraph and conditionality to the root could afford her more range and potentially even damage. A delay could open up the possibility to prime her W before her R initiation so it goes off while she's in stasis, giving her an even greater initiation fantasy.
My goal with these changes are to increase her effective range so she's more comfortable against ranged opponents, whilst making her a bit less hard counter-y against immobile melees. I believe these W and Passive changes would allow her to have a more versatile laning experience in terms of both farming and trading .