Messy divorces, heart disease
This spirit is more an element of a spell than a legend or spirit. According to Bellenger and the Sword of Moses, he is a part of a magical attack, and seperates an enemy from his wife. He also can inflict pain, inflammation and dropsy (caused by a bad heart). There’s a metaphorical connection there between heartbreak and heart condition that would be poetic if Iabiel wasn’t just a name-drop in an incantation. Iabiel is one of those creatures that might be either a demon or a dark angel.