Slormancer features many different builds across different characters. The mage build is one of the most preferred as it’s easy to scale damage even if you have random items that are +0. Thanks to the mechanics of Reap What You Sow and Time Manip, you can deal significant amounts of damage without any hassle and pushing for stronger items. It’s also easy to play with and roam around. While it’s easy to scale damage, it’s quite hard to scale offense and you need to mind the damage you’re taking. This build is also very unlikely to foresee a nerf as it’s balanced yet very powerful.
There are plenty of different Slormancer mage builds but the one shared by the Reddit user u/765Bro is the one that deserves the most credit. The build is very creative and doesn’t take much time to understand, making it simple for everyone. Head over to his Docs file to see the in-depth Slormancer mage build.