I got the game two days ago and now I have 2*. Since my equipment's are 2* I would need Warm fire crystals to level them up. i searched the wiki on how i was able to get them without doing missions and I found out there was a recipe.
Like what the title says, Where can I get the recipe?
I'm not an expert on this, but my understanding is that you get the recipe by doing missions, and there is no other way to get it.
Of course, you can also find Warm Fire Crystals by playing in the Clockworks --- particularly Stratum 2, which is depths 5-7.
You can also buy fire crystals from the Supply Depot, using energy. You can buy energy using crowns.