Karn's Baneshell

Equipped Creature Gains +3/+3, Flying, Deathtouch, Double Strike, And gains:"Whenever Equipped creature attacks, add {u}{u}{u}+ The amount of blue lands you control." This has indestructible as long it is your opponent's turn. If the artifact is equipped 1-2 turns after casting,
this has indestructible.
Equip {4}{u}