Complex sentence: She tells the gatekeeper of the underworld that she wishes to attend the funeral rites of Ereshkigal's husband Gugalanna, but, in "The Epic of Gilgamesh", Gugalanna is the Bull of Heaven, who is killed by Gilgamesh and Enkidu.
Split into simpler sentences: She tells the gatekeeper of the underworld that she wishes to attend the funeral rites of Ereshkigal's husband, here said to be Gugalanna. In "The Epic of Gilgamesh", Gugalanna is the Bull of Heaven, who is killed by Gilgamesh and Enkidu.