It effectively works like a temporary land that upgrades, and then sacrifices itself
The option to run multiple legends in the command zone allows for a ton of deckbuilding flexibility
Many versions of this effect came after, but rarely do they count the creatures that die under an opponent's control as well
In multiplayer, people like to run mana creatures as accelerants, but they have issues because they die, inadvertently, to stuff like Earthquake, Mutilate, or Wrath of God
Gideon, Ally of Zendikar Ally of value Gideon has always been a fairly decent planeswalker in MTG thanks to his ability to become a creature, turn sideways and just slam into nearly anything without having to worry about it