There was no question about it. As knights of Astopol, they were duty-bound to slay the monstrous and inhuman wherever they went, and Rift Beasts were no exception. Even if they stayed the course to track the serial killer down, the killer would no doubt go to ground with the emergence of the Rift Beast, rendering it a moot point to begin with. 

"Agreed." He said curtly, drawing his greatsword. "The killer's most likely going to flee with this Rift Beast around, which renders continuing the hunt pointless." He sized the monster up while considering the capabilities of his comrades. They'd all been briefed on what each other could do before they'd left Astopol, so coming up with a strategy wasn't difficult.

"An overwhelming first strike is likely our best opening gambit. I suggest that Ambroise use her Sword Arts to take it off guard before we three follow up and assault it."