- All gear that drops during the boost;
- The selected amount of Reservoir Anima;
- Various activities completed.
The Reservoir Anima is a currency needed to fuel your Covenant Reservoir required to upgrade mandatory Covenant systems such as the Covenant Sanctum, the Transport Network, the Anima Conductor, the Adventures Table, and other Covenant specific Buildings.
It is also used to start Adventure missions or to buy cool Covenant mounts, pets, transmog gear, and other rewards.
Upgrading these systems is a crucial part of your character's progression. It will also allow you to get some really valuable things such as spawn the Adventures missions which reward with Soul Ash which can be used to craft and upgrade your Legendary gear.
You can also get the Chronicle of Lost Memories which is obtained by completing special tasks at the Anima Conductor which grants you some random Legendary Powers. Keep in mind that in order to farm the desired amount of Reservoir Anima and get all those rewards, you will need to do tons of content every day for several months.