A Vergil Type Enemy is a character, usually the protagonist's rival or
nemesis, that resembles and directly antagonizes the
later.
This character does so through a variety of factors, such as;
Having a similar apparel or design, most cases using a color scheme paralel to the one of the protagonist.
Or having a design that completely visually opposes the protagonist's looks.
Using techniques, fighting
styles, or weapons that resembles the protagonist's own way of brawling.
Their inspirations and morals
go against the protagonist's, strongly colliding each other's.
And many other topics.