Thanks to Fimbulwinter, a lot of the curses are weakening, but Odin's curse on Freya binding her to Midgard still remains strong. However, thanks to Kratos and Atreus discovering realm travel, Freya has found a way around this; she turns into a bird (although this form is very limited). They travel to Vanehaim together to lift the curse.
Forest Ancients are formed from the magic of the Vanir, and unlike proper Ancients, form and fall apart in the span of a single season.
The Shatter Star Shield bathed in the light of a thousand dying stars and is a force of the cosmos. This interestingly enough, let's us know some more on the nature of the stars (there are dying stars, though if these stars are giant balls of plasma & gas or something else entirely is still unclear).
The Glaive of Dodher is said to be able to cut through any surface and is synonymous with death.
Nidhogg can open tears in the fabric of space, which she does whenever she needs to appear somewhere the roots of Yggdrasil are under threat (Odin uses this to his advantage to protect things, such as the curse binding Freya).
Nidhogg draws in energy into her stomach to attack.
Nidhogg can open realm tears at will to attack through them.
Wisps are powerful manifestations of runic magic. They are impervious to physical attacks unless hit with a special kind of magic.
Freya used to be able to remember the faces of all of her worshippers.
This at absolute minimum would include thousands of people.
Soul Eaters are soulless Ancients who eat souls.
The Seal of the Falling Star is the seal of a great warrior who was renowned for dropping down on his enemies with the might of a falling star. This also helps to further reveal the nature of the stars (there are indeed falling stars & meteors).
Like Sindri and Brok, Linda can also (somehow) travel between realms.
It wasn't just through diplomacy that Freyr stopped the fighting between the light elves and the dark elves; his very presence as a god also helped keep a (fragile) peace.
Hati chases the Moon, turning night into day.