Ember

A living embodiment of fire of varying size. She can take pretty much any shape desired although will she usually take the appearance of of a human figure with multiple arms as default, as she grows in power and size she generally has more of them.

Abilities
For sustenance she consumes and stores heat/fuel. As more is stored Ember will evolve and grow in power and intelligence. On the offensive side of things Ember is able to draw upon this store in a way similar to mana and weaponize it if need be. Ember can also grant fire enchantments later on in her evolution.

Evolution
Embers evolution comes in five stages- The first is her purest and most vulnerable, capable of flight although limited in that it must avoid the strong winds of high altitudes. At this point she is not very effective in combat and has the intelligence of a child. The second is larger, about the size of a cat. To reach this stage Ember requires about as much heat as a couple fireplaces might give. This is where the ability to throw fireballs etc is acquired. She is now also less vulnerable to high altitude winds allowing less limited fight. The third stage reaches the height of a young adolescent, able to give weak fire enchantments to items and do significantly more damage. The rough heat a furnace or two would provide is required for this stage. The forth stage is her most intelligent and is about a head in height over fully mature adult. At this stage Ember is capable of dealing out some extreme damage. The heat required for this stage is tremendous and unlikely to be acquired in day to day life. The fifth sage is Ridiculously powerful and dangerous but there is no way short of Ember flying into an erupting volcano that the required amount of heat could be acquired.