Chandra Mangal Yuti Yoga is formed when moon (chandra) and Mars ( Mangal) are in yuti (less than 3 degrees apart). This Yoga is most effective when Mars is behind Moon. Moon is the karaka for mind. Mars has aggression. This yoga can make one’s mind unstable (depending in which house and rashi this yoga happens).
On Positive side, this yoga can give fruits like Laxmi Yoga. Natives with Chandr-Mangal yoga in 10th house, 11th house can benefit from this.
When Chandra Mangal yoga occurs in Krittika Nakshatra (specifically the 1st pada), there is danger from fire. Lord of Krittika Nakshatra is Fire. The first pada of Kruttika is in Aries, whose lord is Sun. There is a lot of heat formed due to this. Hence, for the native with chandra-mangal yoga in kritika, if this yoga is in 4th house, his house has danger form arsenal.