What it does
Armor Cannon is a Fire-type special move with exceptional base power. After it fires, the user's Defense and Special Defense both drop one stage. That's a real cost in doubles, where both opponents can exploit the gap. The payoff is that the raw damage output can KO or severely wound targets that nothing else can one-shot.
Think of it as a precision strike, not a spammable move. You deploy it at the moment it ends a threat, then deal with the defensive penalty.
Who runs it
Armarouge (66% usage) is the primary user. Fire/Psychic type with high Special Attack. Its Flash Fire means it can absorb incoming Fire moves — sometimes useful for soaking up a teammate's spread Fire attack to boost its own damage. The 66% usage rate reflects a solid but situational role; not every team needs it, but those that run it use it meaningfully.
How to use it
Fire Armor Cannon when one of these is true: the target is in KO range and nothing else closes out; the opponent's fastest threat can be eliminated before it acts again; you have a Protect turn or a switch queued on the following turn to mitigate the defensive drop.
After using it, either have your partner deal with remaining threats that turn, or switch Armarouge out. Staying in after the drop means taking heavy punishment from both sides.
If Flash Fire is active and a teammate carries Heat Wave, the interaction can push Armor Cannon damage further — confirm whether that interaction functions under Champions rules before building around it.
Tips & strategy
One Defense/Sp.Def drop makes Armarouge vulnerable to both physical hits like Earthquake and special hits like Shadow Ball simultaneously. Before each use, run the quick mental check: what does this KO, and what does the next turn look like?
If there's no clean KO available, a Protect turn is often more valuable than a weaker Armor Cannon. This move is a win-condition trigger, not a filler attack.
Pairing Armarouge with Choice Specs amplifies the damage further, but locking into one move means once you fire, you're committing to a switch or a clean win — plan accordingly.