I think for every kill, the players should get rewarded by a regen on the special bar... but NOT by that much... Thats just too much regeneration from one kill. You can watch this video [fairly old] and see that from every kill, like 1/7 to 1/8 of the bar is filled after each kill is gotten by this player and personally I think thats too much. PLEASE Bungie take a look at this. I Think it should take about 10 kills to earn a special without any other boosts from skills and stuff.