Answer:
The detail about the Norse god Loki that could be deleted without loss of essential information about him is the fact that the frost giants join him.
Step-by-step explanation:
This excerpt about Norse god Loki gives a full and very detailed description of him as well as his behavior and general actions, the fact that the giants join him can be deleted in that specific sentence since it remains being said in the rest of the excerpt and it does not affect the specific information about Loki since it focuses more in the action of the giants.