Final answer:
While Sykes is dying, the reality that hits him is the consequences of his abusive behavior towards Delia.
Step-by-step explanation:
While Sykes is dying in the story, the reality that hits him is the consequences of his abusive behavior towards Delia. He realizes that his mistreatment has led to Delia finally standing up to him and telling him to leave her house.
This reality hits him when he sees that Delia is no longer afraid of him and is willing to assert herself. Despite his initial threats to hurt her, he doesn't carry through with them because he realizes that Delia is no longer willing to tolerate his abusive behavior.