none of this actually describes what Nick Fuentes was doing but it's not as simple as castle vs stand your ground. important to know if you own a gun or plan on taking a trip to Berwyn

720 ILCS 5/7-2

A person is justified in the use of force against another when and to the extent that he reasonably believes that such conduct is necessary to prevent or terminate such other's unlawful entry into or attack upon a dwelling.

Illinois also has a (roundabout) home defense exception in 720 ILCS 5/7-1 but I'm not sure if it's argued this way in court. Residential burglary is a "forcible felony"

A person is justified in the use of force against another when and to the extent that he reasonably believes that such conduct is necessary to defend himself or another against such other's imminent use of unlawful force. However, he is justified in the use of force which is intended or likely to cause death or great bodily harm only if he reasonably believes that such force is necessary to prevent imminent death or great bodily harm to himself or another, or the commission of a forcible felony.

note that this also does not impose a duty to retreat. You can use (non-deadly) force whenever it's necessary to defend yourself or someone else. Don't trust legal blogspam read the law yourself