First of all. Shit like this is why I don't pay attention to the sensationalist news reporting anymore. There is no story to this 'story'. The boy's family let him stay with his Grandmother AFTER he had already assaulted her, AND been arrested, AND been taken to the hospital, AND been released.
Anybody have a look at the original article? They quote some local nobody that had waved to the kid once. "Yeah, he seemed like a nice shy kid". Theres a picture of a sword on the same page as the news article - but they do not say anywhere on the page that "this is the murder weapon". So its more likely that someone dug up stock sword photos. If they had a picture of the actual sword, there would be law enforcement people in the picture holding the murder weapon.
So a screwed up kid assaulted his family again, that is not news. But because there was a second sword involved, and somebody mentioned the word 'videogame', now we have something. Now the titillation-driven news media perks up and takes notice.
This is not news. Go read a book.
Better yet, write one. November is National Novel Writing Month.
...
Also: the news article didn't say that the sword was sharp. Blunt force trauma works on Great-Grandmothers.