You can even mix things up with a binder system for bulk cards and display cases for your top-tier stuff
Ill try my best to explain required understanding, but know that Arena does a great job of holding your hand until you feel comfortable with the system
However, it's not hard to prevent cards from leaving your opponents' graveyard, especially in Commander
Cast Berserk only before the combat damage step
Because they count as lands and creatures, you can use board wipes like Flood of Tears and Ondu Inversion to remove everything except your animated lands, leaving you with the only board presence in the game
Due to this card's effect, cards can't be placed in security stacks, therefore [ST10-14 Chaos Degradation]'s "place 1 of your opponent's Digimon face down at the top or bottom of your opponent's security stack" can't be activated, and the target Digimon will be left as-is