Obsidian Gate

Obsidian Gate enters the battlefield tapped.
{t}: Add {1} to your mana pool.
{7}, {t}: Sacrifice Obsidian Gate. Destroy all
non-King creatures.
Solemn are the kings who grind their kingdoms into dust. Victory, chiseled in placards by men who ravage thier own kin. Toiled by the meek, plundered by the unworthy.