First off , let me say that you should avoid charging into a Lulu , cause that's not how you kill her. Lulu's weakness is poke. She hates it and has zero that she can do against it. But if you are going to charge head first into a Lulu , use AOE. Technically , Lulu can only defend one person ( Yes , she can shield herself and ulti her teammate , or vice versa. But if she does that , she loses a large chunk of defensive power ). So if you catch both her and say her adc in a Amumu ulti , you should be able to get at least one of the two , probably the one that got the non ultimate shield