The downside is that most options you find require you to buy a significant minimum number of units or boxes and this is sometimes 15-20 such items
In addition, a keyword in a secondary color wouldn't get the ability for the same cost as the primary color
That was the basic through-line with every installment for a while, and even many of the later games that leaned back on the series' crystalline origins
Theres a bit more flexibility with instants and sorceries because they dont stick around, but its hard to understand what youre looking at when your opponents board is in black-and-white
If they do, then as blockers are declared in the combat phase, that battle's protector chooses which, if any, creatures they control will block that attacking creature
You need multiple players at once