Allusion is a figure of speech that refers to a well-known story, event, person, or object in order to make a comparison in the readers' minds.
Eris is the Goddess of chaos, strife, and discord. Eris got herself and a lot of other people in trouble, so much so she is the one believed to cause the Trojan war. She was not appreciated by the other gods, and this caused her not to be invited to Peleus and Thetis wedding.
Once Eris found that she was uninvited to the wedding she dropped off the Golden Apple of Discord. The goddesses fought over this apple to find out the fairest one of them all. This apple caused Zeus to find some else other than home to choose, so he found the prince of Troy to decide. The Golden Apple of Discord has become known as Eris' symbol.
In Much Ado About Nothing Benedick refers to Eris' daughter Ate, when he is describing Beatrice. I think Shakespeare decided to use this allusion to represent how Benedick felt about Beatrice at the time. Benedick thought she was Beautiful, but mischievous and caused chaos everywhere she went.
"She’s as wicked as Ate, just disguised in pretty clothes. I wish to God that some wise man would conjure her away, because as long as she lives on earth, our lives are filled with turmoil."
- Benedick Act 2, Scene 1, Page 11
The Goddess Eris' story relates to the conflict in Much Ado About Nothing because it was both about ruining a wedding. In Much Ado About Nothing Don John is like the Golden Apple of Discord because they are the reason why there was so much conflict in the story, but no one realized this at the time.
"ENCYCLOPEDIA." Ate. N.p., n.d. Web. 6 May 2015. <http://www.theoi.com/Daimon/