If in any direction it has no more than one allied piece directly in front of it (cover), then at least (two? three?) unoccupied spaces between that ally and an enemy piece, it can take aim at an enemy piece.
The next turn, if those conditions are still true, it can fire, capturing the target piece.
An enemy piece adjacent to the target piece that could move into the line of fire can be sacrificed to take the bullet instead, though.
The sniper.
Intriguing, but does it have to have a meat shield?
It could probably either have to have a meat shield or have to take one turn to aim before firing but not both