I assume you are referring to the Lilliput in Gulliver's travels, and in the story the Blefuscudians are the enemy of Lilliput.
The solution is (5,-2) red line is for 1st equation and blue line is for 2nd
The right answer is eum because 'him' is the object in the sentence. In Latin the object always gets expressed by using the accusative . The accusative form of is, ea, id ~ is 'eum'!
Your answer is Feminine, hope this helps.