The archetypes is presented in five pages: cover, one and a bit pages of description and two of OGL. It could use more context for the archetype such as suggestions for where they might fir into a game world and what sort of culture would inspire them. Also, and this is very common for such materials, is a lack of support material such as a new spell, magic item, place or even a legend to inspire adventure would make them some much more interesting and easier to fit into a campaign.
Phoenix Sorcerer tapping into the flame and rebirth of the phoenix is a good theme and, as they get some access to healing spells, they will likely be popular. They can cheat death, if they have sorcery points remaining, and make dramatic escapes from danger (taking their friend with them) but that should probably reset on a long rather than short rest though. Overall, thematic and fun.
Good work from a good starting point.
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