We waited 6 months for promised lissandra buffs and this is what we get?

untargetable 30% slow and super delayed damage, both gated behind enemies dying. This will do nothing to help lissandra. Her problems were that she didnt do enough damage and that she was too squishy. This new passive will give her some utility and also minor (but extremely avoidable) damage in teamfights but shes still left super weak in directly fighting people and also surviving.

The added utility is nice (albeit not great considering it relies on enemy positioning) but they really need to add some form of survivability boost to this statue passive unless the aoe is like as large as her ult.

Her burst will still be too weak to be a successful burst mage. Her cooldowns will be too long to be a battlemage. Her range is still too low to be an artillery mage. This passive wont even improve her ability to catch.

I cant reiterate this enough that it's a neat mechanic but it really fails to address her primary issues, she still wont be able to fight anyone on her own

Why not just let her collect ice shards from cc'd enemies that provide her with shield based on AP, you literally wouldnt even have to change the icon ffs and it would synergise super well with her 3 cc's and dive focused kit.