Xenoclea, the Oracle of Delphi

Hexproof
{t}: Target creature gains Shroud and
Vanishing X, where X is the creature's casting cost.
Sure though thy feet, proud Sparta, have a care,
A lame king's reign may see thee trip — Beware!
Troubles unlooked for long shall vex thy shore,
And rolling Time his tide of carnage pour.
-Plutarch