The last time Dan Stevens turned up in an Adam Wingard movie, he was pulling an achy tooth out of Kong’s mouth in Godzilla x Kong: The New Empire. It was hard to imagine the longtime collaborators topping that gloriously absurd aerial-veterinarian sequence. But somehow, they may have done it with Onslaught, trading a medical transport chopper for something far more grounded and bizarre. Onslaught is a John Carpenter- and James Cameron-inspired action-thriller that serves as an indirect sequel to Stevens and Wingard’s cult hit The Guest (2014), completing a spiritual trilogy that began with Wingard’s 2011 home-invasion slasher You’re...