Spheres of Might
Spheres of Might is a system developed by the creators of Spheres of Power, it is currently in play test but it is allowed with the caveat that if anything appears to be over-powered or disruptive to gameplay the GM reserves the right to modify or ban the content.
The conversion rules for classes can be found here. If you are playing any of the following classes, please read the link above carefully. If you plan on using the Spheres of Might system and playing one of these, you need to read the above link. Alchemist, Antipaladin, Barbarian, Bloodrager, Brawler, Cavalier, Fighter, Gunslinger, Hunter, Investigator, Magus, Monk, Ninja, Ranger, Rogue, Samurai, Slayer, Swashbuckler, Thaumaturge, and Vigilante.
And the additional rules for this system may be found here.