This is my updated ShineGreymon deck. Where do I even begin? This deck is extremely fast and aggressive now. It is also extremely consistent thanks to Agumon X and Digital Gate Open with the Koromon. Digital Gate Open lets you play out your Marcus for free when you have your GeoGreymon out which triggers its effect to evo for free into a RiseGreymon. Depending on the RizeGreymon you can then either play out another Marcus or you can turn the previous Marcus into a Digimon and give it alliance and let it immediately attack. Note this is for free. You can then Digivolve your RizeGreymon into a ShineGreymon for free using the Marcus's effect while allience is active with the ShineGreymon stack. -5K to your opponents entire board and security. Now that Marcus is a triple breaker. You can then go into a burst mode on your ShineGreymon which bounces the Marcus back to hand to play it back out. Marcus then gets rush and can immediately attack. That is all five of your opponents security gone on turn two and you didn't even spend any memory to do so. All you need to do now is have one more way of doing security during this turn and your opponent is out of the match entirely. This is of course a high roll. But what happens with a low roll? Good ol ShineGreymon beatdown.
