Adam Wingard’s Onslaught is coming in hot, and it just picked up an R rating for strong bloody violence, grisly images, language throughout, and some sexual references. If you were hoping Wingard would hold back, it doesn’t sound like that’s happening.

The upcoming A24 action horror film reunites Wingard with longtime collaborator Dan Stevens, and that’s only added fuel to a fan theory that’s been circulating ever since the first trailer dropped. Many horror fans are convinced Onslaught could somehow be connected to The...