The Sword Volume 1 Fire by the Luna Brothers
Paraplegic art major Dara Brighton goes home to have dinner with her parents and sister. They have a pleasant evening until three strangers arrive at their suburban home. The strangers call the father "Demetrios" and demand that he turn over a sword. He denies any knowledge of them or a sword. They search the house. Finding nothing, they decide to torture the information out of dad. They use supernatural elemental powers to harm the family but the dad doesn't give in. They kill the mother and the sister and then start in on Dara. The dad grabs at them and they decide to torture him instead. The female stranger has air elemental power and uses electrical energy on him (which you'd think would go with a fire-based power, but it isn't here). She overdoes it, killing the dad and setting the house on fire. The strangers decided to leave after some of the roof collapses on Dara. They assume she'll die in the fire. She actually falls through the floor into a pit under the house where she discovers an ancient sword. She grabs onto it and her legs are healed. She races out of the house and hides the sword in their pond as the cops show up. She pretends to be crippled as they ask her what happened. She's vague about the details because she doesn't want the cops hauling her off to the nut house. Things get out of control quickly after the three strangers (who are siblings) find out Dara survived the attack. They make plans to get their sword back. But Dara has discovered that the sword not only heals her, it also gives her superhuman fighting and jumping skills, so things aren't as unevenly matched as they might otherwise be.
The story moves at a good pace and explains a lot of the mystery behind the sword by the end of this first volume. The characters are interesting and believable. The art is good, though I find the occasional blurring of an image to indicate speed a bit distracting. The violence is pretty graphic, with lots of people getting cut into pieces by the sword, but they don't dwell on the gore like The Walking Dead or Mark Millar's stuff tends to. It's an enjoyable read and I am ready for volume 2!
Parental warning: in addition to the heavy violence mentioned above, the language is very adult (lots of f-bombs, for example), and there's one mild sex scene that include drug taking (though it really has almost nothing to do with the plot). Late teens and up would be my recommendation.