Sivir's spellshield doesn't work correctly with leblanc's chains.
When chain hits sivir and sivir uses spellshield (which should protect from dmg and snare) doesn't actually work in this way. I'm almost sure that any kind of spellshield doesn't work with lb how it should.
passive stacks
I may do some research on this later, i'll do a post about it then, because it's super stupid what it will and won't block :/