It's an italian exclamation used when people are angry, scaried and similar . It is a General insult to Christ, and it's similar to porco dio, mannaggia lamadonna, dio cane.
examples :
-"Mannaggia Cristo è finita la benzina della macchina!" ("Mannaggia Cristo the car's gasoline is over!")
-quando torni a casa da lavoro ed è in ifamme: "Mannaggia Cristo !"(when you come back from office to home and your house is in flame:"Mannaggia Cristo !")
A sophisticated and eclectic piece of blasphemy most popular in Rome. Grave insult directly to the Baby Jesus. Usually used in scenarios of extreme rage and/or pain.
blaspheme expression used in moments of intense anger and wraith against god, it is used frequently when something of very important goes wrong or something bad happened.
"mannaggia i sandali di cristo, mi hanno tamponato! " "mannaggia i sandali di cristo mi hanno licenziato!"