2xLegendary Land

[BreathWeapon]

For example, I have a Tomb of Urami on the board, I tap that Tomb of Urami for black mana, I have a Tomb of Urami in hand and now what is the timing regarding casting the second Tomb of Urami and being able to either tap it for black mana or sacrifice it for its effect before both legends are sacrificed due to the post Kamigawa legends ruling? Is there any difference if I control both lands or my opponent and I both control the same land?

[Sanguine Voyeur]

When you play the second, state based effects are checked and you don't have the opportunity to tap it for mana. You also don't have the chance to sacrifice it for its ability either.