Essentially, if you have a full party with all four of these on the board, you can pay one white, one blue, and one black mana to give the Warrior lifelink, deathtouch, and make him unblockable (deathtouch and unblockable at the same time has no real use, but thats still OP to think about)
But blue doesn't just draw cards - it controls the flow of the entire game
This area is known for its alternating dry and rainy seasons, with the nomads leaving during the rainy seasons
Unless the Dimir player can counter them early on, theyre left bargaining with other players to remove them
Unfortunately for us, I think Papa Leo here is Commander-only
At this point, they realized that they needed to keep their cards value high or people wouldnt collect them at all