Until now the dark ghos is the only unit I found with an 200% damage on critical hit. Looks for me this is special (found only dark Robobot so far with the same +100% with (same) natural 10% crit probability)? The tankier light version has a 100% stun on critical hit. This is similar to the fire Monkiki with 100% (sleep) on crit, however I barely see this Monkiki crits in practical (natural crit rate = 10%). The crit rate of the light Ghos (checked with my Spiritus and assume the ascension did not raise this) is 20% (for comparison).