Tide Raiser

At the beginning of each player's upkeep, target land becomes an Island until the beginning of the next end step.
Tide Raiser is a 4/4 Construct artifact creature as long as you control four or more Islands.
The Collective adapted to the complex tides of Aelam millennia ago. On arriving on Edgerim, they decided it would be easier to change the tides than change their habits.