Where does “焔” come from?

焔 (Japanese) comes from Japanese 炎, from Old Japanese 炎, from Old Japanese 火, from Proto-Japonic poy, from Proto-Japonic po.

Ancestry of “焔”, step by step

Step	Language	Word	Meaning
1	Japanese	炎	a flame; an intense emotion, passion; -itis,...
2	Old Japanese	炎	a flame
3	Old Japanese	火	a fire; a light
4	Proto-Japonic	poy	fire
5	Proto-Japonic	po	—