In fact just to make things a bit easier, here's a list of who needs a nemesis:
[list]
	[*] Villains
		[list]
		[*]Vantablack
		[/list]
	[*] Heroes
		[list]
		[*] many lols
		[/list]
[/list]
The people who currently have nemesis are: 
[list]
[*]portal - Falcon
[*]Infamous - Dreamscape
[*]Ignis - The Kineticist (unofficial)
[*]Therma - Red Demon
[/list]