Pretty simple, basically a block with a transparent (or maybe PlexLight, like beacons) texture, which holds a missile effect inside it, including both the 'flare' particle and the trail. You could link it to any light source to change the color. Applications include funky engine glows and trails, trails on disintegrator missiles, weird spiral things using rail rotators, smoke trails for airplane-style space fighters, working nyan cats, and more! This block would also be toggleable by logic.