Asgardian Keep

Asgardian Keep enters the battlefield tapped.
When Asgardian Keep enters the battlefield,
return a land you control to its owner's hand,
then you may pay {1}. If you do, target creature
gains vigilance until end of turn.
{t}: Add {u}, {r}, or {w}.
Whenever Asgardian Keep is tapped for mana,
add {c}.