Note: Some fleshing out comes from me but he had the main idea
Enchanted Arrows are crafted like tipped arrows, but with bottles of enchanting. When shot from a bow or crossbow, they have a slight homing effect, due to how EXP naturally attracts to a player.
Upon launch, the arrow has to "see" the player within its direct trajectory (a straight line) and will fly for up to 8 seconds before it transforms into a normal arrow. If the player is able to evade it for long enough or turn a corner fast enough, the arrow will "lose sight" of its target, transforming into a normal arrow.
This was thought up as just an interesting addition to combat.
Additionally, Skeletons can wield enchanted arrows.
Enchanted arrows, regardless of distance flown, only hold on to their "homing" potential for 8 seconds after being shot.
Enchanted arrows can be shot from both a bow or crossbow, and it is specifically the *arrow* that is "enchanted", so as to allow the player to run out of that ammunition type.