Board Thread:Boruto Discussions/@comment-43689784-20200520151938/@comment-32685487-20200525024209

Even if she attacked him by surprise, she mortally damaged him and he couldn't fight back. We saw Madara move and fight with just his upper half as a TTJ and Kinshiki still move and fight after he got fucked up by the 5 Kage. Isshiki just didn't have the power or durability to beat Kaguya, only enough to survive being bisected.