Kira's hunger has finally reached its limit. She no longer remembers what happened over the last few days. Her empty stomach has driven away her sanity and brought back her demonic nature. In order to satiate her hunger, Kira kills whatever creatures she comes across and eats them whole. Her eyes burn bright red, revealing the hereditary demon tendencies within her.
Kira is the the Japanese word for killer. Japanese took the word killer and put in katakana as a kira.