>>4012937You see, almost any sin can be deadly according to catholic teaching (as long as it is done consciously, willingly and harmed someone substantially, latter is usually read as 'involved a grave matter').
The original concept of "Seven deadly sins" was, if I am correct, created by some catholic saint, but it was mistranslated. Originally it meant something like "Seven deadly FLAWS of man", the most common and generally worst sins one could commit.