A celestial creature's CR increases by +1 only if the base creature has 5 or more HD.
A celestial creature's quick and rebuild rules are the same.
Senses The creature gains darkvision 60 ft.
SR The creature gains spell resistance equal to its new CR +5
Special Attacks The creature may smite evil 1/day as a swift action (it adds its Cha bonus to attack rolls, and a damage bonus equal to its HD against evil foes; smite persists until the target is dead or the celestial creature rests).