You brandish the weapon or spellcasting focus used in the spell's casting and make a attack or cast a spell with it against one creature within 5 feet of you or 30 feet when using a spell. On a hit, the target suffers the weapon attack's or spells normal effects, and you can cause green fire to leap from the target to a different creature of your choice that you can see within 5 feet of it. The second creature takes fire damage equal to twice your level.