I have to start off by saying, the new passive looks great, but I can't help but feel like it adds "too much" to the kit. What I mean by that is that, in a teamfight, where it's already very hectic, it adds another layer to it. There's a lot to keep track of, but at least most of those can be "countered" in terms of either side-stepping or flashing/using items, whereas Lissandra's statues/ghosts are too impactful without having much to counteract it.
The fact that statues stack (no CD between statues) without even having Lissandra need to damage them will create a case (like Karthus) where they go AFK farm, get a bunch of items (like Zhonya), and just go in and let the team do the rest, having your statues clear everything on their own. I've had a game where Lissandra killed 1 person, getting a Triple Kill from the sheer amount of damage the statue did to the other 2 players.
If I had to suggest, put a CD between statues spawning from enemies, or make Lissandra have to damage the enemy for him to spawn a statue upon dying (like Fiora's heal from her ult only if she hits at least 1 mark). This might be biased, as well as inaccurate considering I wouldn't have enough experience playing/facing her, as well as the skill difference on PBE, so if you don't agree with me, I'd love to hear your opinion about this.