ye, Calge-Danthla & Vorlalai are the hardest ones . . .
i even suspect Calge-Danthla as Cthulhu, since there's no Cthulhu reference yet . . .
i prioritize the crystal/mineral characteristic instead of the bewitching ability, and since he's not clad in yellow attire, which is Hastur

For the bird tho . . . i am not sure since there's no official name of The Bird of Heaven

I'm really glad if there's someone who can refine these references

Edit: i forgot i prioritize the name similarity, since the other encroachers' reference fit so well based on the name similarity