You could test decks you were prototyping, try out some screwed up terrains, and most importantly play with your friend if he brought his save on a memory card
You could even take two different commanders that share a color, and build a larger module for each that allows you to swap between commanders while keeping the same base theme intact
Serra Angel In the early days of Magic, a clean, powerful creature with no downside was a big deal, and Serra Angel was exactly that: a 4/4 flier for 5 mana that also has vigilance, meaning it can attack and still stay back on defense
#132: Z/X Z/X (otherwise known as the impeccably silly Z/X Zillions of enemy X ) is another waifu TCG, but good lord, you would not know it looking at this angsty card back
Of course, the one downside to this game is that the base game suffers from a shallow level of content