For those that are curious about what Wave-Motion Cannon is and/or how it could act as a pressure card
Wave Motion-Cannon
Continuous Spell
Text: During your Main Phase, you can send this card to the Graveyard to inflict 1000 points of damage to your opponent for each of your Standby Phases that have passed since this card was activated.
Spell cards are a lot like Trainer cards; there are "Normal Spells" that work like Item cards, "Field Spells" that work like Stadium cards, "Equip Spells" that work like Pokémon Tools, etc. There are a few that don't have a Pokémon TCG equivalent; Continuous Spells are one of them, and are a bit like a cross between an Item and a Stadium. They stick around after you play them, until a card effect (sometimes their own) discards them. They aren't "attached" to any other card in play, though, unless that particular Continuous Spell states it works that way. There is another mechanic called "Traps" we won't be discussing, as I don't wish to make this even longer or more confusing for those who don't know Yu-Gi-Oh... but for those who
do know, I need to state this so that it isn't confusing for them. XD
Yu-Gi-Oh turns start with the Draw Phase, basically like Pokémon, but before you continue to the Main Phase where you can play most cards from your hand (not unlike Pokémon), there's the Standby Phase where various effects resolve. Victory comes when your reduce your opponent's Life Points to zero. Players each start with 8000 Life Points. Put it all together, and you can see how an ignored Wave-Motion Cannon wins you the game in nine turns; play it and 8 turns later you can use its effect to do 8000 damage. While I played Yu-Gi-Oh (basically from its North American launch until 2009), Wave-Motion Cannon was rarely (if ever) competitive. It flirted with it at times, as a pressure card. Rarely would your opponent fail to destroy Wave-Motion Cannon, even though that required the effect of another card to accomplish, Spell removal effects were common. Including cards that could wipe out multiple Spell/Traps at once. Still, sometimes a card like this was useful to distract from your
real goals, so you'd drop it early game (if it showed up...) and your opponent
had to deal with it or lose. Hence the name "pressure".