Gil chooses the word Ea because he likes it.
But I think Nasu choose the words Ea because of this reason:
"he crisis is finally ended by Ea, the god of wisdom.
Ea visits the place of the ancient primeval gods, gets from their storehouse a copper cutting instrument "
which was used to separate the earth and the sky", and,using it, cuts Ullikummi from Ubelluri's shoulders."
- Taken from
http://rbedrosian.com/Memyth.htm under topic of Kummiya/Qumme. Credit to Aldeayeah of Beast's Lair.
__________________
Fate/Zero: This was the tale of a man who, more than anyone else, believed in his ideals, and was driven to despair by them.
Madoka: This was the tale of magical girls whose wishes are pure and by them are driven to despair.