When Bad Castle enters the battlefield, return a land you control to its owner's hand.
: Add or to your mana pool.
Put Bad Castle on top of your library: Add to your mana pool.
, : Target Kor Knight gets +1/+1 until end of turn.
: Add 
or 
to your mana pool.
to your mana pool. , : Target Kor Knight gets +1/+1 until end of turn.
