Killer Concept: The Strategist
The Strategist is a M1 killer, not using any kinda speacial attack to effect survivors. The Strategist's ability is simple yet versatile. His ability is called stats. Hold M2 to open a menu. In this menu you have different stats, such as speed, lunge distance, stun time, ETC. You also are given a set amount of points. You can invest these points into stats to increase them, or decrease in the case of stun time. You can always remove previously invested points from a stat and add them to another. Addons are simple. They either give you more points or effect how much 1 or more stats are increased by per point. There are also addons that can give you passive abilities in exchange for points, like applying a status effect to injured survivors.
Unlike most killers, the counter play depends on the playstyle of the person playing as killer. A good Strategist main changes their playstyle and stats around to deal with counter play or certain survivor playstyles. Basically this killer doesn't have a particularly strong ability but is extremely hard to counter play.