#kinoko

Canon Touya threw around some words about being reborn. The way he seems mentally stuck to his childhood felt like a Phoenix who can't (or perhaps won't) allow himself to grow beyond a certain point, doomed to repeat his self-destruction. Like the other villains though - he's much more morally grey in this story.

Firebird (Slavic) are often harbingers of either good fortune, doom- or unattainable goals in their tales. If that doesn't sound like Endeavor I'm not sure what does. They differ from phoenix in which they are 'always on fire', but they don't self immolate - they're just 'built like that'.

Tsurara onna (icicle woman) are created from the loneliness of single men during the winter time. When a man gazes longingly at a strong, beautiful icicle, they may appear. They disappear in the summer, and may reappear in winter. The love stories invariably end in tragedy. Considering Rei's dynamic to Enji, it felt fitting.

A Snegurochka (Russian- Snow Maiden) the fairytales often echo tsurara onna, of maiden that melts due to "shenanigans" (not always tied to love stories). 

Simurgh (Persian) is more of a reach - you can really dive into their different lore and variations, but they are similar to phoenix in which they also immolate to reincarnate after a very long time. They have connections to both fire and water.

There's no myth creature equivalent of both fire and ice. Yet in canon, Shoto is the only one who doesn't provide himself a hero title. His name is his identity. So- he's the only "undefined" creature. There's a number of myths you could read him as if you wanted (he doesn't care).

... Dabi's pheonix fire also plays into forming the character Juzo (Not that anyone asked- this is reaaaaaaaallly reaching into the semantics on the yliaster, or prima materia that forms the philosophers stone- which mentions pheonix fire purification as a metaphor... ah don't worry about it).