Use Compact FATE as written. The system would support easily a tale of classic heroes.
Take the skills for Exalted. Group the skills by Caste, and reduce them to 15 all in all, combining the Ride and Sail, Dodge and Athletics, Stealth and Larceny, Bureaucracy and Linguistics, Lore and Investigation, Medicine and Occult, Melee and Martial Arts, Archery and Thrown, Presence and Integrity, Survival and Resistance.
Exalts should be Better Than Mortals, and better than each other. This results in the famous "power tiers", which are represented by the scaling rules. Every time you've got an opposed test, add the difference in levels as a difference in levels of Scale.
Yes, that makes a single Solar equivalent to an army of mortals. That's a feature of the setting. Also, Martial arts are a way to get above your level!
The progression goes as follows.
Solaroids, Celestial Akuma, anyone who can practice Sidereal Martial Arts, if those exist in your version of the setting, and the Yozis.
Celestials, non-Celestial Akuma, Half-Castes and anyone practising Celestial Martial Arts and Third circle demons
Dragon-blooded and anyone practising Terrestrial martial arts, Second Circle demons.
God-blooded and other X-blooded, First Circle Demons.
Unenlightened Heroic Mortals
This can easily vary, though, according to your preferences. Keep in mind that getting access to powerful martial arts can get you up in this level.
Facing someone more than a couple levels above you, unless your strengths directly oppose their weaknesses, typically results in you losing, though. That is, unless you can oppose the more powerful by a squad of people like you, nullifying their advantages... Also see the Ususrpation
Charmtrees are simulated by Stunts, and are custom-built by the player and GM. Note, most stunts should be paid for with FATE points, which are renamed to "Essence" for this game.
Stunts give you back Fate Points and increase the results, as usual.