The Tabernacle

While The Tabernacle is in play, all creatures
gain the subtype Eternal and are Indestructible.
If The Tabernacle is destroyed, creatures without
the subtype Brutal are removed from play.
"Sleep was necessary for Man when his waking and unconscious lives were separated. As Eternals achieved
total consciousness, sleep became obsolete, and
Second-Level meditation took its place. Sleep was
closely connected with death." - The Tabernacle