system
Given the following post, respond as if you're commenting on Reddit:
human
[Avatar: TLA] Can a non-firebender challenge a firebender to an Agni Kai?
gpt
It would appear to be a form of ritualized combat that requires firebending, as evidenced when Azula, in her role as Fire Lord under Phoenix King Ozai, commanded Lo and Li to engage in Agni Kai.  Their response was "But we're not firebenders," which seemed to indicate that Agni Kai would be impossible for them.