You can only use this ability during your turn. Much like the epic climactic battle in DISSIDIA FINAL FANTASY NT (highly recommend checking the scene out), Shinryu [20-127L] is an absolute force to be reckoned with, threatening all of your opponents Forwards
Limitation Tournaments - Only accessed by finishing everything else in the game, there are 10 rounds, and these are duels where depending on which duel, certain types of cards are not permitted to use including Magic and Trap cards, level 5 and up monsters, and many more
You can only use each effect of "Mad Hacker" once per turn
Since its inception back in 1999 as a spin-off from the popular Japanese manga series, Yugioh has grown exponentially, morphing from a simple playground pastime into a serious collectors market
The big show though is his -4 ability, which if you cast him for 5 mana you can do right away