Feasible engine for a world like Earthsea? [closed]


I am building a world emphasising on balance and chaos (where pretty much two sides of one coin), kind of like Earthsea.

As a consequence, the magic in D&D doesn’t work quite well with it. (powerful magic exists in my world, but unwise usage of powerful magic usually comes with deadly consequence.)

Also I want the bad consequence lasts longer, kind of like sanity in COC.

What is a feasible system for my world? Or any feasible way to modify any system to make it work? Or do I have to create one myself (I hope not)?