Answer:
The universal themes covered by the description of battles between Beowulf and Grendel and between Grendel's mother are:
Reputation
Honor
Loyalty
Ambition
Regret
Envy
Hospilality
Responsibility
Pride
Explanation:
First of all, Beowulf is an epic story about a warrior that fights for different causes but that all of them have moral value fundaments. In the first place, he tells the story of how his father was protected by a king and that because of that Beowulf owes loyalty to that man. Also, Beowulf fights for a king and follow his commands. But that reputation makes him decide between the presentation of Grendel's head or the king. However, after that Beowulf is tempted by Grendel's mother and makes a deal with her for ambition, pride, and reputation. So, after many years he has to face the son he had with Grendel's mother and he regrets his actions. Envy is also represented in the story by Grendel and how he is envious about men because god blessed them but not him.
