"Distraction!" Was all Sirius had time to yell at Marco. As he did he hefted the sword back and threw it like a javelin. The sword wasn't aerodynamic at all and while it was arcing towards the Basilisk, it was going to miss it entirely. That's where being a wizard came in handy.

"Leviosa!"

The sword straightened out, and Sirius aimed it at its head. The Basilisk's mouth wasn't open but he managed to slice off part of its tongue. The Basilisk hissed.