XP streake enchantment

I know there have been multiple XP enchantment ideas, but I feel like this one is unique. You don't directly gain more XP from killing mobs with this enchantment, but you begin a streak. The more mobs you kill, the higher this streak, the higher the streak, the more XP mobs drop. This streak would obviusly under a time limit. 

Sincerely,

- T Posing Ermit