That's when Legolas appeared, using his arrows and knives to kill the spiders, after which, they point their arrows at the dwarves. "Do not think I won't kill you, Dwarf. It would be my pleasure", he firmly told Thorin as he kept his stance in front of him, with the arrow aimed at his face. 

As Kili was being attacked by the remaining pack of spiders, Maleficent appeared from the trees, starts killing the spiders. It seems she had a lot of muscle and speed to kill them, and it also appears that she was flying. Her wing was healed! Agile maneuvers like any other elf, her dagger and her sharp finger cuffs being her only shape weapon, she killed at least half of the pack.