Torrent, the Riverblade

Equipped creature gains trample and gets +X/+X, where X is the number of rivers you control.

When equipped creature deals combat damage to a player, look at the top four cards of your library.
You may put a river from among them onto the battlefield tapped. Put the rest on the bottom of
your library in any order.

Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)