Dagger Mastery

Your time spent practicing and using such weapons allow you to have additional bonuses while wielding a dagger. 

You gain the following benefits:

• When thrown, within 5 feet or before your max range of throwing, your attacks are not rolled with disadvantage. 
• Critical hits are scored with a natural 19 or 20 (If already a 19, it becomes 18, 19, or 20)
• You may attack with a dagger as a bonus action instead of an action.
• When an ally within 15 feet get's hit by a melee attack you can expend your reaction to throw your dagger in an attempt to hit their assailant. If this attack connects (in addition to any damage dealt) you can,  because of the speed and strength of your reactionary dagger throw, can subtract 1d4 from their attack roll so as you may cause the attack to miss.