Lissandra Passive
I kind of just thought about this from watching different champions and came up with a passive that to me makes a lot of sense for her rather than that auto attack passive they were thinking about implementing into the game. Anyways here it is.
Icy Trail: dark ice follows Lissandra's path. If a champion walks on it they are %slowed based on level and are grounded (debatable because I am not sure if Riot plans on just keeping that on Cassiopeia or not). On death, Lissandra's body seeps into the ground around her creating a circle of dark ice with the previous effects.
I got the idea because of the way she moves and her kiting ability would be intense
Long Live The Frostguard! 
Let me know if the idea is just plain terrible or good. To me it makes a lot of sense really.