Elecomun is the name of a Legacy that gives the user the ability to generate and manipulate currents of electricity.
Erina tried to gain his trust by flying above his house, with his Chimæra, and created brilliant light displays, fireworks made from electricity. Despite not trusting her, Raylan would return to the courtyard day after day to watch her and in courtship of her power, Raylan would use his Light Manipulation to manipulate the colour of Erina lightning strikes. Raylan enjoyed himself for the first time in many years. This would eventually lead them to get married.
Elders with the title of Pittacus Lore are able to replicate any Legacy they have seen using Ximic. This including Elecomun as well.