Modpack Magic and Sorcery by Speshel_

This modpack includes Mana and Artifice as the focus, allowing you to play as a Sorcerer and progress through multiple tiers, unlocking more powerful spells.
By progressing, you can craft custom spells with near infinite possibilities. Clearing entire forests, destroying enemies with flames raining from the sky, pretty much whatever you can think of.

You'll find many different structures through the world giving unique spells as well, which allow for some even crazier combinations.

There are also incredibly strong bosses in the Nether and End that you can find and defeat using magic.