The Elder Wand

Equipped creature has Double Strike and +3/+0.
Equip: {3}{r}{r} (The Elder Wand gets equipped to
the creature until it dies.)
When the equipped creature dies in combat,
exchange control of The Elder Wand with that
Player.
There are gaps, of course, and long ones, where it
vanishes from view, temporarily lost or hidden; but it
always resurfaces.