{T}, Sacrifice this artifact: Each player exiles all cards from their hand face down and draws seven cards. At the beginning of the next end step, each player discards their hand and returns to their hand each card they exiled this way.
"Every device in the rig is evidence of Thran enlightenment. All mana was the same to them, whether from rock or water, growth or decay. Can you imagine such unity of vision?" —Urza, journal
Echo {4} You may choose not to untap this artifact during your untap step. {2}, {T}: All creatures get +2/+2 for as long as this artifact remains tapped.
Forbidding Watchtower enters tapped. {T}: Add {W}. {1}{W}: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.
This land enters tapped. {T}: Add {B}. {1}{B}: This land becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land.