Nova Rocket
The Nova Rocket is given to players as a loaded firework crossbow. When a player shoots the firework out, the crossbow breaks and the firework flies out in a straight line, leaving a trail of particles colored after the the player’s team. It will then explode whatever it hits first or wherever it ends up after a maximum 1.5 seconds of flight.
In addition, the Nova Rocket explosion launches any nearby enemy players into the air (via 4 ticks of Levitation 60), dealing additional firework damage to those players at their peak height (15 ticks after they are first hit). If the resultant explosion kills any players, the player who shot the Nova Rocket is credited for the kill.
When two enemy Nova Rocket fireworks collide during flight, a green particle burst known as a Nova Rocket Collision occurs, dealing increased explosion damage at the point of collision. In this circumstance, no players are credited for the kill.
Use Cases
The Nova Rocket may be used in a very similar manner as Fireballs to destroy or otherwise disable enemy missiles. Since they have a limited range, the Fireball may be a better choice for more distant targets, but since Nova Rockets fire instantly and also launch the players they hit, they may be more preferable in some cases.
The Nova Rocket may also be used to instantly explode enemy Canopies. Such an explosion is practically guaranteed to also instantly kill any players on top of the Canopy.
Like arrows, the Nova Rocket can be shot at a Vortex to instantly explode it (also killing the firework in the process).
Also, like Fireballs, Nova Rockets may be launched at the middle glass pane in an Obsidian Shield to weaken it by one damage stage and perhaps destroy it.
Note that they cannot be launched directly at exposed portals to end the game (in most gamemodes, anyway) unless the Snipe Portals game rule is enabled.
Gamemode Specific Behavior
In Chase Mode, players may use Nova Rockets defensively against their teammates as friendly fire is enabled and only Blue team is joinable. Nova Rocket Collisions are impossible in this circumstance, but players may be launched or may even launch themselves with Nova Rockets.
In Powerups Mode, Nova Rockets can be used to set off End Crystals.
The Nova Rocket is not obtainable in Swap Mode.