Trafalgar D. Water Law

Whenever Law enters the battlefield create a
room token.
Law gets +1+1 for each room you control.
{u}{b}{r}: create a room token.
{t}:exchange the control of two target nonland
permanent that share a card type until you
control a room.
{u}{b}{r},{t}: take control of target non-land
permanent with mana value les than law power
until you control a room.