One of your players came to you with something that they wrote of found online and they want to play with it in your game. Rather than simply rejecting it, what can be done to balance homebrew content while still retaining what your players like about a homebrew character option.
DnD 5e - Dungeon Master Resources
Van Richten's Guide to Ravenloft introduces a new and exciting character option called "Dark Gifts.” While ostensibly flavored as pacts or offerings from dark entities that come with strings attached, these Dark Gifts can be made to fit many settings with a little tweaking of flavor.
Tasha's Cauldron of Everything introduced the concept of "Optional Class Features", which offer powerful new options to customize and improve classes' core features. Rather than allowing them across as-written for every character, I encourage a more reasoned, thoughtful, and precise approach.
A mechanical breakdown of planning out the content and rewards of a campaign from levels 1 to 20.
A detailed guide to planning and running tight, impactful, and fun game sessions within a one-hour timeframe.
A detailed guide to what Sidekicks are, how they work, how to use them in your game, and how to create your own sidekicks.
A guide to using magic items in your campaign as a reward, as a plot device, as a balancing mechanism, and as a window into the lore of your world.