Cuddox Vulso, Duty-Bound

Cuddox Vulso, Duty-Bound's power and toughness are each equal to the number of creatures on the battlefield.
If Cuddox Vulso, Duty-Bound's power is 5 or greater, he has vigilance. If his toughness is 10 or greater, he has double strike.
Partner (You can have two commanders if both have partner.)