From Trigun. Cosplayer is Ex-Shadow.
The main protagonist of the anime and manga series of Trigun. Vash is also known as The Humanoid Typhoon due to the destruction and chaos that often surrounds him. Wielding a huge silver revolver, he travels from town to town to learn more and protect what his adopted mother, Rem. He is initially discovered by Meryl Stryfe and Milly Thompson, two Bernardelli Insurance Society representatives investigating claims made due to damages caused by the mysterious Humanoid Typhoon. Vash's silly behavior hides the fact that he is a gunman of extraordinary skill, and he is almost always able to avoid capture by his opponents and defeat them easily without killing them. He spends most of his time traveling from town to town, getting into and out of trouble and making sure everyone survives, often hindered (and sometimes helped) by his fearsome reputation. (trigun.wikia.com)