The twins are still looking for a pack and to get on Scott's good side they're flanking him as protection against the demonic ninjas. Scott teases them with his True Alpha-ness.
Stiles, perhaps the dark spirited Nogitsune Kitsune the Oni are after, reaches into the chest of the Oni and tears his heart out. It is released in the form of a firefly.
All Kira had to do was touch Scott's face and reveal she's one of the 13 trickster spirits known as Kitsune to really catch the eye (and lips) of Scott!
