Emrakul, the Aeons' Shipped

Flying, Indestructible
Other creatures you control have Soulbond.
Emrakul, the Aeons Shipped gets +1/+1 for each creature that's paired with another creature.
As long as a creature you control is paired with another creature, it has lifelink and "This creature gets +1/+1 for each other creature you control that is paired with a creature."