The amount of Void energies that Tyrande is wielding at Darkshore is incredible; Alleria Windrunner herself would admire her abilities.
The balance druids are the chosen of Elune -- they wield Life (solar energy) and Arcane (lunar energy) at the same time.
The Priestesses of the Moon are the servants of Elune -- they wield Light and Arcane at the same time.
The Night Warrior is the avatar of Elune -- they wield Light and Void at the same time.
Elune's powers also extend to the Shadowlands -- she brought Ysera there, and she is able to continue to directly assist Tyrande in the afterlife. So she has some powers over Death.