(A player with ten or more poison counters loses the game.) Losing the game because a player (preferably an opponent) has ten or more poison counters is a rule of the game
It wasn't that long ago that precons would need several swaps to function, and that doesn't even include the mana base
Amethyst/Steel was also very good, especially in its aggro or midrange variants with help from cards like Azurite Sea's Genie and Gantu
Note that it avoids casting your Commander, so it won't be countered or subject to a Commander tax
Thanks to the durable, non-slip surface, you can enjoy a comfortable and stable base during your games, while your cards are optimally protected from damage
if you open a legendary land or a Dragon in this slot, you'll get an extended-art version