My idea for a reworked Lissandra passive

DISCLAIMER: Now before I start, I am under no delusions that I know balance, this is just to get and idea out there so that maybe a Rioter sees it and gets inspired.

Frost Aura The Ice Witch's presence on the rift is not only seen, but felt.

While the name isn't anything original, I think it's fairly obvious what this is. It's an aura(duh) that applies a stacking debuff, the amount applied depends on the proximity of enemies to Lissandra. At max stacks, enemies explode in a Frost Nova that damages and roots/stuns them briefly. Her spells will also apply one stack of her passive, with her Q applying 2 to the initial target and(I know I'm probably going overboard here) enemies struck by her ult have the initial target's passive stacks spread to them. I really would love love love, to see something like this implemented because it's so cool(heh) and in my opinion, thematically sound. The idea of Lissandra's presence not only being seen but felt in the form of extreme cold is, personally, such a satisfying and fulfilling gameplay fantasy.

Now again, if it's broken, I wouldn't know because I'm just tiniest bit biased. So if you don't like it, that's fine, post an idea of your own. Get those creative juices flowing and let's get our favourite Ice Witch a new passive.