Death's Eyes

Prerequisites: Proficiency in a rifle weaponry, or rifles in general. Proficiency in Ranged Weapons. The feat's boons will be disabled if you can't see or sense your target in anyways.
Years of bonding and training with your rifles have granted you the ability to line up your shot for a perfectly calculated fatal blow. When facing most creatures, you know exactly where and how to hit a target in a manner that'll struck the harshest blow possible. (Provided that, of course, you, or your character, is aware of such frailty on said target.). This feat grants your character those benefits:

• Take Aim, As an action, you can choose to carefully aim your next shot, granting you Advantage on yours next attack roll made with the rifle. If you pick this action again, your next attack that's made with the rifle will be made with advantage, and it is a critical hit if it lands. However, if you move or is forced to move before your next attack, you'll lose all benefits gained from this action; additionally, due to the recoils from the rifle, if you don't have 18 Strength, then this action will only buff one and only one attack that is the first attack you made with a rifle on your turn.

• Analyse, If you, or your character isn't aware of a certain target's weak point, then you can analyse a creature's weakness to figure out where is best to strike. As an action, you can roll either a Perception, Nature, History, or Investigation check depending on the circumstances, and the higher the roll, the more weak points discovered. Additionally, the skill check chosen also affect the outcome of said roll - for example: a successful Nature or History check may allow you to find textbook weaknesses of certain creatures that you learned through educations or reading in generals; but successful checks made with Perception or Investigation skills may allow your character to discover weak points that otherwise would have remained hidden: maybe the target had a wound that has yet to fully heal, or it was sick, infected with certain kind of diseases or poisons that cause certain parts to be weakened. After a successful analysis, you can also choose to relay the information to yours allies, allowing them to exploit such weaknesses.

• Being prone doesn't impose disadvantage on your ranged attack rolls, provided that they're made with a rifle.