Kindlegem and Glacial Shroud stack
Both items have the same unique passive.
Unique: +10% cooldown reduction
And yet, if you have both in your inventory at the same time, you don't get just 10% cdr, you get 20% cdr even though they shouldn't stack.
5 Comments
+200 health (not unique. will stack as many kindlegems as you get)
Unique Passive: +10% CDR (unique, only 1 kindlegem will provide this)
If the Unique has a name, such as 
Legion, then any Legion buff won't stack regardless of the item that has it. If there is no name, then different named items will stack it. All CDR items have Unique CDR passive so that getting a bunch of that item won't stack it, but getting different CDR items will.
I think it's that different items with the same Unique NAMED passives don't stack with each other (like the Immolate passive from Bami's Cinder and it's upgrades). However, if an item has a unique passive that isn't named, it just means that you can't get that same passive from the same item, but you can get it from a different item.
I think that since they're not named, they don't stack if you have multiples of the same item.
Kindlegem won't stack with another kindlegem, but it will stack with glacial shroud.
Wait, I am so late to this party.