They're pretty ungrateful. Like seriously who the fuck tests the person who's allowing them to stay in their house, not to mention they haven't contributed anything at all. If I was him i'd show them a smile and tell them to pick up their weight before I throw them into the woods as bait.
Yeah... This story just became a manga version of the TV series "Heroes" (2006 - 2010). https://en.wikipedia.org/wiki/Heroes_(American_TV_series)
The TV series had a villain - ("Sylar" - played by Zachary Quinto) - whose superpower was the ability to steal another hero's superpower by killing them. Sound familiar?