Take the mechanics of the Halo 2 Flying Covenant Plasma Sword, and turn it into a proper weapon. Heck the Knights already basically did this in Halo 4, except with silly warping zig-zagging.

Give it to the player, make it take more skills and precise timing the greater the distance. Include Jump Lance only Slayer. New players just smash each other in the face with it, Pro players freaking snipe you with it from the edge of the map.

Heck yeah!