When you determine the size of the game that you want to play against your opponent, that determines the minimum and maximum values. So if you want to play using BeLakor, you'll need to be playing at least a 2000pt game (2000/4 = 500pts) and then yes, Belakor will use up all of your Lord points. You could still take up to 500pts of Heroes however. The percentages are parts of your total army value. The percentages are:ok thanks yeah i understand actually seams to make sense!
so to use be'lakor who is 500points, i'd need 2000 of whatever he can join, daemons or warriors of chaos with no other lords or heros allowed?
sorry i'm still abit new when it comes to the fantasy percentage bit!