Portal of Sauron

{t}, Add {u}, {1}, {w}, {u}, {b}, {r}, {g}, {c}, {e}, {b/g}, {b/r}, {g/u}, {g/w}, {r/g}, {r/w}, {u/b}, {u/r}, {w/u}, {w/b},
When this land enters the battlefield, create a 1/1 Slave token with '{t} create a token that is a copy of this creature.'
Sacrifice a Slave: Create a Treasure artifact token with 'sacrifice this artifact and add {1} mana of any colour to your mana pool.'