Clutch Shot

You are a Crack Shot, making shots worthy of impressing the highest of royals and mightiest of heroes. And you want to help your side despite being half a football field away, ultimately you came up with a solution.

Aiding Shot. When an allied creature is about to roll a Saving Throw, or a Contested Roll use your reaction to Add your Dexterity Modifier to their roll.
(Caveat being the Allied Creature this was used on must now take half the damage from your ranged weapon, it can be flavored in any way but they must take the damage. And subtract the ammunition used from your inventory)

Impeding Shot. When an enemy creature is about to roll a Saving Throw, or a Contested Roll use your reaction to Subtract your Dexterity Modifier to their roll.   
(Caveat being the Enemy Creature this was used on will take no damage from the Ranged Weapon. And subtract the ammunition used from your inventory)

Can be used an amount of times equivalent to your Dexterity Modifier, or Proficiency Modifier at your DM’s discretion. Recharges fully on a long rest, and halfway on a short rest.