The first expansion of 2021 for Path of Exile, Echoes of the Atlas, comes with new loot and new builds.
When you are done with the current version of the endgame, the new system will activate. The Maven, a mysterious entity, will challenge each player into a fight. Each battle will be harder than the previous one. At some point, the entity will challenge the player into a duel. Defeating her will give you unique, powerful rewards.
Her presence in the game adds a new passive trait to the skill tree. You get a point every time you defeat The Maven. The new points will not go into your character. Instead they will be invested on an activity you want to do in the endgame. The purpose of this is to give the player the freedom on choosing what type of endgame they want. Another item The Maven drops are the Waystones.
Echoes of the Atlas returns Heist and Harvest to the game. In addition, Ascendancy Classes have gotten a rework.
There is also a new Challenge League called Ritual. Nothing is different in this new Challenge besides the fact that players can stumble upon Altars surrounded by monsters. The purpose of the Atlars is to bring enemies back to life that is empowered by unknown magic. The reward, Tribute, given after defeating the enemies will be based on the type of Ritual you are performing.
Go forth and have fun!