has officially launched Season 7, which is the Season of Witchcraft. During this season, you can access extra perks, such as Witchcraft Powers, that give you various abilities, such as flaming crows coming to attack your enemies every few seconds.
On top of that, you can also craft and use Occult Gems, which provide bonuses to your Witchcraft Powers. Because of this, the Tree of Whispers will be your hub during this season since it's where you can access and craft most of your seasonal perks.
Perks such as Witchcraft Powers and Occult Gems are only available to seasonal characters, which have you start from Level 1 again without access to your usual stash or items from normal characters.
However, Paragon points from Season 7 will transfer to your normal characters once the season ends. Even without that bonus, playing with Witchcraft Powers is fun enough to justify starting a seasonal character for Season 7.
Occult Gems act like normal socketables, but they provide bonuses to Witchcraft Powers instead of normal abilities or the resistance bonuses that regular gems tend to have for jewelry. You have to craft Occult Gems, but you need to get recipes to craft them.