(Dormant River isn't a spell.)
Dormant River enters the battlefield tapped.
Each creature you control can't be blocked except by two or more creatures.
: Add or to your mana pool.
: Add to your mana pool. Put Dormant River on top of your library.
: Add 
or 
to your mana pool.: Add 
to your mana pool. Put Dormant River on top of your library.
