Percy Jackson, Son of The Sea

As long as you control one or more Islands, Percy Jackson has islandwalk.
As long as you control three or more Islands,
Percy Jackson has hexproof and "If a source
would deal damage to Percy Jackson, prevent all
but 1 of that damage."
As long as you control seven or more islands,
Percy Jackson has "Merfolk, Krakens, Leviathans, Octopuses, Serpents, and Crabs get +1/+1 and
have hexproof."